laravel Method Illuminate\Validation\Validator::false does not exist

I believe you are looking for fails, not false, from the Laravel documentation:

<?php
 
namespace AppHttpControllers;
 
use AppHttpControllersController;
use IlluminateHttpRedirectResponse;
use IlluminateHttpRequest;
use IlluminateSupportFacadesValidator;
 
class PostController extends Controller
{
    /**
     * Store a new blog post.
     */
    public function store(Request $request): RedirectResponse
    {
        $validator = Validator::make($request->all(), [
            'title' => 'required|unique:posts|max:255',
            'body' => 'required',
        ]);
 
        if ($validator->fails()) {
            return redirect('post/create')
                        ->withErrors($validator)
                        ->withInput();
        }

so your code is going to be:

<?php

namespace AppHttpControllersApi;

use AppModelsUser;
use IlluminateHttpRequest;
use IlluminateSupportCarbon;
use AppHttpControllersController;
use IlluminateSupportFacadesِAuth;
use IlluminateSupportFacadesHash;
use IlluminateSupportFacadesValidator;


class UserController extends Controller
{
    /**
     * Create User
     * @param Request $request
     * @return Response
     */

    public function createUser(Request $request)
    {
        try {

             $validateUser = Validator::make($request->all(),
            [      
                'name'=> 'required',
                'email' => 'required|email|unique:users,email',
                'password' => 'required'
            ]);

            if($validateUser->fails()){
                return response()->json([
                    'status' => false,
                    'message' => 'validation error',
                    'errors' => $validateUser->errors()
                ], 401);
            }

          $user = User::ceate([
            'name' => $request->name,
            'message' => $request->email,
            'password' => $request->password
          ]);
           
            return response()->json([
                'status' => true,
                'message' => 'User Created Succssfully',
                'token' => $userInfo
            ], 200);

        } catch(Throwable $th){
            return response()->json([
                'status' => false,
                'message' => $th->getMessage()
            ], 401);
        }
    }

}

See Laravel documentation for more information.