laravel inserting into multiple tables

Controller

<?php

 

namespace App\Http\Controllers;

 

use App\User;

use App\DB;

use App\Father;

use App\Mother;

use Illuminate\Http\Request;

 

class PassportController extends Controller

{

public function register(Request $request)

    {

        $this->validate($request, [

            'username' => 'required|min:3',

            'firstname' => 'required|min:3',

            'lastname' => 'required|min:3',

            'email' => 'required|email|unique:users',

            'password' => 'required|min:6',

        ]);

 

        $user = User::create([

            'username' => $request->username,

            'firstname' => $request->firstname,

            'lastname' => $request->lastname,

            'email' => $request->email,

            'password' => bcrypt($request->password)

        ]);

      

        $data = Father::create([

            'user_id' => $user->id,

            'fathername' => $request->fathername,

        ]);

        $datad = Mother::create([

            'user_id' => $user->id,

            'mothername' => $request->mothername,

        ]);

        //dd($data);

 

        $token = $user->createToken('TutsForWeb')->accessToken;

 

        return response()->json(['token' => $token], 200);

    }

Model  user

<?php

namespace App;

use Illuminate\Contracts\Auth\MustVerifyEmail;

use Illuminate\Foundation\Auth\User as Authenticatable;

use Illuminate\Notifications\Notifiable;

use Laravel\Passport\HasApiTokens;

class User extends Authenticatable

{

  

    use HasApiTokens, Notifiable;

    /**

     * The attributes that are mass assignable.

     *

     * @var array

     */

    protected $fillable = [

        'username','firstname','lastname', 'email', 'password',

    ];

    /**

     * The attributes that should be hidden for arrays.

     *

     * @var array

     */

    protected $hidden = [

        'password', 'remember_token',

    ];

    /**

     * The attributes that should be cast to native types.

     *

     * @var array

     */

    protected $casts = [

        'email_verified_at' => 'datetime',

    ];

    public function insertdata(){

        

    }

}

Model Father

<?php

namespace App;

use app\User;

use Illuminate\Database\Eloquent\Model;

class Father extends Model

{

    protected $fillable = [

        'fathername','user_id',

    ];

}

Model Mother

<?php

namespace App;

use app\User;

use Illuminate\Database\Eloquent\Model;

class Mother extends Model

{

    protected $fillable = [

        'mothername','user_id',

    ];

}