настройка апи
public function init()
{
parent::init();
\Yii::$app->response->headers->set('Access-Control-Allow-Origin', '*');
\Yii::$app->response->headers->set('Access-Control-Allow-Headers', 'Content-Type');
\Yii::$app->response->format = Response::FORMAT_JSON;
\Yii::$app->user->enableSession = false;
\Yii::$app->errorHandler->errorAction = 'site/error';
}