Unable to Access Java Object From Core Module Class LibGDX Android Studio

I’m trying to create an Android project with a game inside of that project. I found a Java development game framework called LibGDX. When I was trying to use it, I got several problems. First, Inside a class that extends ApplicationAdapter in the core module, I’m unable to call all of the Java object like String, error said:

Cannot resolve symbol 'String'

The second problem is all of the Gdx object having some errors like:

Cannot access java.lang.Object

Cannot resolve constructor 'Texture(java.lang.String)'

The weird thing: with the second problem I can still installing and running it.
I have been trying to fix the Gradle but it doesn’t work. This is my build.gradle

buildscript {
    

    repositories {
        mavenLocal()
        mavenCentral()
        gradlePluginPortal()
        maven { url "https://oss.sonatype.org/content/repositories/snapshots/" }
        google()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:4.2.1'
    }
}

allprojects {
    apply plugin: "eclipse"
    apply plugin: "idea"


    version = '1.0'
    ext {
        appName = "TestGame"
        gdxVersion = '1.10.0'
        roboVMVersion = '2.3.12'
        box2DLightsVersion = '1.5'
        ashleyVersion = '1.7.3'
        aiVersion = '1.8.2'
        gdxControllersVersion = '2.1.0'
    }

    repositories {
        mavenLocal()
        mavenCentral()
        google()
        gradlePluginPortal()
        maven { url "https://oss.sonatype.org/content/repositories/snapshots/" }
        maven { url "https://oss.sonatype.org/content/repositories/releases/" }
    }
}

project(":android") {
    apply plugin: "com.android.application"

    configurations { natives }

    dependencies {
        implementation project(":core")
        api "com.badlogicgames.gdx:gdx-backend-android:$gdxVersion"
        natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-armeabi-v7a"
        natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-arm64-v8a"
        natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-x86"
        natives "com.badlogicgames.gdx:gdx-platform:$gdxVersion:natives-x86_64"
        api "com.badlogicgames.gdx:gdx-box2d:$gdxVersion"
        natives "com.badlogicgames.gdx:gdx-box2d-platform:$gdxVersion:natives-armeabi-v7a"
        natives "com.badlogicgames.gdx:gdx-box2d-platform:$gdxVersion:natives-arm64-v8a"
        natives "com.badlogicgames.gdx:gdx-box2d-platform:$gdxVersion:natives-x86"
        natives "com.badlogicgames.gdx:gdx-box2d-platform:$gdxVersion:natives-x86_64"
        implementation fileTree(dir: 'libs', include: ['*.jar'])
        implementation 'androidx.appcompat:appcompat:1.3.1'
        implementation 'com.google.android.material:material:1.4.0'
        implementation 'androidx.constraintlayout:constraintlayout:2.1.1'
        testImplementation 'junit:junit:4.+'
        testImplementation 'commons-logging:commons-logging:1.2'
        androidTestImplementation 'androidx.test.ext:junit:1.1.3'
        androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
        
    }
}

project(":core") {
    apply plugin: "java-library"

    dependencies {
        api "com.badlogicgames.gdx:gdx:$gdxVersion"
        api "com.badlogicgames.gdx:gdx-box2d:$gdxVersion"


    }
}

The Class:

public class TestGame extends ApplicationAdapter {

    SpriteBatch batch;
    Texture img;

    @Override
    public void create () {
        batch = new SpriteBatch();
        img = new Texture("badlogic.jpg");
    }

    @Override
    public void render () {

        Gdx.gl.glClearColor(1, 0, 0, 1);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
        batch.begin();
        batch.draw(img, 0, 0);
        batch.end();

    }

    @Override
    public void dispose () {
        batch.dispose();
        img.dispose();
    }

}

Any suggestions?

Perhaps this is a basic question, but this LibGDX stuff is somewhat Greek to me.