withdefault laravel

1) if not exists
public function wallet()
{
    return $this->hasOne(Wallet::class)->withDefault([
        'name' => 'Wallet Name',
    ]);
}

2) or force insert when user created please use observer|model boot


    protected static function boot()
    {
        parent::boot();

        static::created(static function (self $user) {
            $wallet = new Wallet(['name' => 'Wallet Name']);
            $user->wallet()->save($wallet);
        });
   }
 Run code snippet