Why does PHP Yandex.Money API SDK return NULL when getting an access_token?

Question

Yii

wrote a code to get an acces_token in pure php, it worked successfully, then the same code was slightly adapted for yii2
, as a result I get the code value, and the access_token returns NULL, I tested all the work on the local without https
for some reason no errors are displayed, although it should, do not tell me in which direction to dig? what could be the problem?

<?php

private
function yandexParams()
{
    $ya['scope'] = array("account-info operation-history operation-details payment-p2p");
    $ya['redirect_uri'] = '';
    $ya['client_id'] = '';
    return $ya;
}

// http://site.loc/frontend/web/site/send-yandex-money
public
function actionSendYandexMoney()
{

    function human_print($var)
    {
        echo '<pre>';
        print_r($var);
        echo '</pre>';
        echo '<hr>';
    }


    $yandex = $this->yandexParams();
    $code = Yii::$app->request->get('code', '');
    // echo 'res yandex money';

    if (!empty($code)) {


        print_r($yandex);
        echo '<hr>';
        var_dump('code', $code);
        echo '<hr>';

//                $access_token_response = API::getAccessToken($client_id, $code, $redirect_uri, $client_secret);
//                $access_token_response = API::getAccessToken($client_id, $code, $redirect_uri, $client_secret = NULL);
        // $access_token_response = API::getAccessToken($yandex['client_id'], $code, $yandex['redirect_uri'],$yandex['client_secret']);

        $access_token_response = API::getAccessToken($yandex['client_id'], $code, $yandex['redirect_uri'], $client_secret = NULL);

        var_dump('$access_token_response', $access_token_response);
        echo '<hr>';

        if (property_exists($access_token_response, "error")) {
            // process error
            echo $access_token_response->error;
        }
        $access_token = $access_token_response->access_token;


        var_dump('$access_token', $access_token);
        echo '<hr>';

    } else {


//            $auth_url = API::buildObtainTokenUrl($client_id, $yandex['redirect_uri'], $yandex['scope']);
        $auth_url = API::buildObtainTokenUrl($yandex['client_id'], $yandex['redirect_uri'], $yandex['scope']);
//            var_dump($auth_url);
//            echo '<hr>';
        return $this->render('yandex-auth.php', [
            'auth_url' => $auth_url,
        ]);
    }


    /*********** views ************/
?>
    <form id = "auto-send-yandex-money2" method = "POST" target = "_blank" action = "<?php echo $auth_url;?>" >
    <input type = "submit" value = "Авторизация через Яндекс" >
</form >

Answer 1

dig into decomposition and iteration,
well, the first thing is to compare the data when it "worked" and "corrected a little"

Answer 2

The SDK is no longer supported by Yandex.
Error in old links - the request is sent to https://sp-money.yandex.ru, but should be sent to https://money.yandex.ru