accounts/api/controllers/TwoFactorAuthController.php

<?php
namespace api\controllers;

use api\filters\ActiveUserRule;
use api\models\profile\TwoFactorAuthForm;
use Yii;
use yii\filters\AccessControl;
use yii\helpers\ArrayHelper;

class TwoFactorAuthController extends Controller {

    public $defaultAction = 'credentials';

    public function behaviors() {
        return ArrayHelper::merge(parent::behaviors(), [
            'access' => [
                'class' => AccessControl::class,
                'rules' => [
                    [
                        'class' => ActiveUserRule::class,
                        'actions' => [
                            'credentials',
                        ],
                    ],
                ],
            ],
        ]);
    }

    public function actionCredentials() {
        $account = Yii::$app->user->identity;
        $model = new TwoFactorAuthForm($account);

        return $model->getCredentials();
    }

}