megahunt.test/app/Http/Controllers/PublicUserController.php

<?php

namespace App\Http\Controllers;

use App\Models\User;
use Hash;
use Illuminate\Validation\ValidationException;
use Illuminate\Http\Request;
use Validator;

class PublicUserController extends Controller
{
    public function register(Request $request)
    {
        $data = $request->all()['user'];
        if (User::where([ 'email' => $data['email'] ])->count() != 0) {
            return response()
                ->json('email_taken', 400);
        }

        /**
         * @var User
         */
        $user = User::create([
            ...$data,
            'password' => Hash::make($request->input('password'))
        ]);
        $user->save();
        session('user', $user->id);
        session()->save();
    }
}