Save data in related models

Hi i have problem in saving data when my models are related. i have to tables: admin and admin_token

for admin:

    public $id;
    public $username;
    public $password;
    public $logged_in;
    public function initialize()
    {
        $this->setSource("admin");
        $this->hasMany(
            'id',
            'App\\Models\\AdminTokens',
            'admin_id',
            [
                'alias' => 'Tokens',
            ]
        );
    }

and for admin_token:

    public $id;
    public $admin_id;
    public $is_revoked;
    public function initialize()
    {
        $this->setSource("admin_tokens");
        $this->belongsTo(
            'admin_id',
            'App\\Models\\Admin',
            'id',
            [
                "alias" => "Admin",
            ]
        );
    }

now in controller something like blow wont work:

    $admin = Admin::findFirstByUsername($username);
    foreach( $admin->tokens as $token ) {
            $token->is_revoked = 1;
    }
    $tokens = [];
    $tokens[0] = new AdminTokens();
    $tokens[0]->admin_id = $admin->id;
    $tokens[0]->is_revoked = 0;
    $admin->tokens = $tokens;

    $admin->logged_in = 1;
    $admin->save()

is there any idea why this method not only update token and set them to 1 but also it does not save any token in admin_tokens table?