I'm just learning Flutter and I can't map response data for use

You can use quicktype.io and just paste your json and give a class name and it’ll generate your required model class.

You can play with the available options like:

• null safety
• types only
• generate copyWith method

Here’s the example of generated code from quicktype.io based on your json

// To parse this JSON data, do
//
//     final userData = userDataFromMap(jsonString);

import 'dart:convert';

List<UserData> userDataFromMap(String str) => List<UserData>.from(json.decode(str).map((x) => UserData.fromMap(x)));

String userDataToMap(List<UserData> data) => json.encode(List<dynamic>.from(data.map((x) => x.toMap())));

class UserData {
    int id;
    Owner owner;
    String title;
    String description;
    String imageUrl;
    String content;
    String benefit;
    List<Vote> votes;
    DateTime createdAt;
    DateTime updatedAt;
    int activeStatus;

    UserData({
        required this.id,
        required this.owner,
        required this.title,
        required this.description,
        required this.imageUrl,
        required this.content,
        required this.benefit,
        required this.votes,
        required this.createdAt,
        required this.updatedAt,
        required this.activeStatus,
    });

    UserData copyWith({
        int? id,
        Owner? owner,
        String? title,
        String? description,
        String? imageUrl,
        String? content,
        String? benefit,
        List<Vote>? votes,
        DateTime? createdAt,
        DateTime? updatedAt,
        int? activeStatus,
    }) => 
        UserData(
            id: id ?? this.id,
            owner: owner ?? this.owner,
            title: title ?? this.title,
            description: description ?? this.description,
            imageUrl: imageUrl ?? this.imageUrl,
            content: content ?? this.content,
            benefit: benefit ?? this.benefit,
            votes: votes ?? this.votes,
            createdAt: createdAt ?? this.createdAt,
            updatedAt: updatedAt ?? this.updatedAt,
            activeStatus: activeStatus ?? this.activeStatus,
        );

    factory UserData.fromMap(Map<String, dynamic> json) => UserData(
        id: json["id"],
        owner: Owner.fromMap(json["owner"]),
        title: json["title"],
        description: json["description"],
        imageUrl: json["image_url"],
        content: json["content"],
        benefit: json["benefit"],
        votes: List<Vote>.from(json["votes"].map((x) => Vote.fromMap(x))),
        createdAt: DateTime.parse(json["created_at"]),
        updatedAt: DateTime.parse(json["updated_at"]),
        activeStatus: json["active_status"],
    );

    Map<String, dynamic> toMap() => {
        "id": id,
        "owner": owner.toMap(),
        "title": title,
        "description": description,
        "image_url": imageUrl,
        "content": content,
        "benefit": benefit,
        "votes": List<dynamic>.from(votes.map((x) => x.toMap())),
        "created_at": createdAt.toIso8601String(),
        "updated_at": updatedAt.toIso8601String(),
        "active_status": activeStatus,
    };
}

class Owner {
    int id;
    String email;
    String username;
    String phone;
    bool isActive;
    bool isStaff;
    bool isPremium;
    int activeStatus;
    String authProvider;
    Profile profile;
    List<Following> following;
    DateTime createdAt;

    Owner({
        required this.id,
        required this.email,
        required this.username,
        required this.phone,
        required this.isActive,
        required this.isStaff,
        required this.isPremium,
        required this.activeStatus,
        required this.authProvider,
        required this.profile,
        required this.following,
        required this.createdAt,
    });

    Owner copyWith({
        int? id,
        String? email,
        String? username,
        String? phone,
        bool? isActive,
        bool? isStaff,
        bool? isPremium,
        int? activeStatus,
        String? authProvider,
        Profile? profile,
        List<Following>? following,
        DateTime? createdAt,
    }) => 
        Owner(
            id: id ?? this.id,
            email: email ?? this.email,
            username: username ?? this.username,
            phone: phone ?? this.phone,
            isActive: isActive ?? this.isActive,
            isStaff: isStaff ?? this.isStaff,
            isPremium: isPremium ?? this.isPremium,
            activeStatus: activeStatus ?? this.activeStatus,
            authProvider: authProvider ?? this.authProvider,
            profile: profile ?? this.profile,
            following: following ?? this.following,
            createdAt: createdAt ?? this.createdAt,
        );

    factory Owner.fromMap(Map<String, dynamic> json) => Owner(
        id: json["id"],
        email: json["email"],
        username: json["username"],
        phone: json["phone"],
        isActive: json["is_active"],
        isStaff: json["is_staff"],
        isPremium: json["is_premium"],
        activeStatus: json["active_status"],
        authProvider: json["auth_provider"],
        profile: Profile.fromMap(json["profile"]),
        following: List<Following>.from(json["following"].map((x) => Following.fromMap(x))),
        createdAt: DateTime.parse(json["created_at"]),
    );

    Map<String, dynamic> toMap() => {
        "id": id,
        "email": email,
        "username": username,
        "phone": phone,
        "is_active": isActive,
        "is_staff": isStaff,
        "is_premium": isPremium,
        "active_status": activeStatus,
        "auth_provider": authProvider,
        "profile": profile.toMap(),
        "following": List<dynamic>.from(following.map((x) => x.toMap())),
        "created_at": createdAt.toIso8601String(),
    };
}

class Following {
    int id;
    int follower;
    int followed;

    Following({
        required this.id,
        required this.follower,
        required this.followed,
    });

    Following copyWith({
        int? id,
        int? follower,
        int? followed,
    }) => 
        Following(
            id: id ?? this.id,
            follower: follower ?? this.follower,
            followed: followed ?? this.followed,
        );

    factory Following.fromMap(Map<String, dynamic> json) => Following(
        id: json["id"],
        follower: json["follower"],
        followed: json["followed"],
    );

    Map<String, dynamic> toMap() => {
        "id": id,
        "follower": follower,
        "followed": followed,
    };
}

class Profile {
    int id;
    String user;
    String lastName;
    String firstName;
    int point;
    int exp;
    int streak;
    String avatarUrl;
    int gender;
    DateTime birthdate;
    String height;
    String weight;
    String bmi;
    int level;
    DateTime createdAt;
    DateTime updatedAt;
    int activeStatus;

    Profile({
        required this.id,
        required this.user,
        required this.lastName,
        required this.firstName,
        required this.point,
        required this.exp,
        required this.streak,
        required this.avatarUrl,
        required this.gender,
        required this.birthdate,
        required this.height,
        required this.weight,
        required this.bmi,
        required this.level,
        required this.createdAt,
        required this.updatedAt,
        required this.activeStatus,
    });

    Profile copyWith({
        int? id,
        String? user,
        String? lastName,
        String? firstName,
        int? point,
        int? exp,
        int? streak,
        String? avatarUrl,
        int? gender,
        DateTime? birthdate,
        String? height,
        String? weight,
        String? bmi,
        int? level,
        DateTime? createdAt,
        DateTime? updatedAt,
        int? activeStatus,
    }) => 
        Profile(
            id: id ?? this.id,
            user: user ?? this.user,
            lastName: lastName ?? this.lastName,
            firstName: firstName ?? this.firstName,
            point: point ?? this.point,
            exp: exp ?? this.exp,
            streak: streak ?? this.streak,
            avatarUrl: avatarUrl ?? this.avatarUrl,
            gender: gender ?? this.gender,
            birthdate: birthdate ?? this.birthdate,
            height: height ?? this.height,
            weight: weight ?? this.weight,
            bmi: bmi ?? this.bmi,
            level: level ?? this.level,
            createdAt: createdAt ?? this.createdAt,
            updatedAt: updatedAt ?? this.updatedAt,
            activeStatus: activeStatus ?? this.activeStatus,
        );

    factory Profile.fromMap(Map<String, dynamic> json) => Profile(
        id: json["id"],
        user: json["user"],
        lastName: json["last_name"],
        firstName: json["first_name"],
        point: json["point"],
        exp: json["exp"],
        streak: json["streak"],
        avatarUrl: json["avatar_url"],
        gender: json["gender"],
        birthdate: DateTime.parse(json["birthdate"]),
        height: json["height"],
        weight: json["weight"],
        bmi: json["bmi"],
        level: json["level"],
        createdAt: DateTime.parse(json["created_at"]),
        updatedAt: DateTime.parse(json["updated_at"]),
        activeStatus: json["active_status"],
    );

    Map<String, dynamic> toMap() => {
        "id": id,
        "user": user,
        "last_name": lastName,
        "first_name": firstName,
        "point": point,
        "exp": exp,
        "streak": streak,
        "avatar_url": avatarUrl,
        "gender": gender,
        "birthdate": birthdate.toIso8601String(),
        "height": height,
        "weight": weight,
        "bmi": bmi,
        "level": level,
        "created_at": createdAt.toIso8601String(),
        "updated_at": updatedAt.toIso8601String(),
        "active_status": activeStatus,
    };
}

class Vote {
    int id;
    String user;
    String userId;
    String blog;
    int voteValue;

    Vote({
        required this.id,
        required this.user,
        required this.userId,
        required this.blog,
        required this.voteValue,
    });

    Vote copyWith({
        int? id,
        String? user,
        String? userId,
        String? blog,
        int? voteValue,
    }) => 
        Vote(
            id: id ?? this.id,
            user: user ?? this.user,
            userId: userId ?? this.userId,
            blog: blog ?? this.blog,
            voteValue: voteValue ?? this.voteValue,
        );

    factory Vote.fromMap(Map<String, dynamic> json) => Vote(
        id: json["id"],
        user: json["user"],
        userId: json["user_id"],
        blog: json["blog"],
        voteValue: json["vote_value"],
    );

    Map<String, dynamic> toMap() => {
        "id": id,
        "user": user,
        "user_id": userId,
        "blog": blog,
        "vote_value": voteValue,
    };
}

So you can just paste those generated models in your code in a dart file.
And when you need to map the response you can just use something like this:

final model = ModelName.fromMap(yourJsonResponseString);