ServerErrorResponseException when calling PageSpeed API

I'm working on a task and I've encountered the following exception when trying to reach out PageSpeed APi:

ServerErrorResponseException
Server error response
[status code] 500
[reason phrase] Internal Server Error
[url] http://ift.tt/2ugdYSB

On my local development PC everything works perfect, but on the server it throws this exception. I've tested and curl is enabled and working on the server. When I make a curl request for the same url from the terminal of the server it works but not from the site. I'm using VueJS and Laravel for it. Here is my code:

1. With VueJs I make an axios POST request to my API Controller which loops the selected urls and makes the request to PageSpeed for them:

   runTest() {
    for (var i = 0; i < this.selectedProjectUrls.length; i ++) {               
     axios.post
     ('/api/'+this.selectedProject.slug+'/'
      +this.selectedProjectUrls[i].id);
    }
   }
   
   

   Here is my Controller's logic

   public function save(Project $project, Url $url)
   {
    $pageSpeed = new PageSpeed();
    $test['mobile'] = $pageSpeed->getResults($url->name, 'en_US', 'mobile');
    $test['desktop'] = $pageSpeed->getResults($url->name, 'en_US', 'desktop');
   }
   
   

Here is my PageSpeed Service logic:

class PageSpeed
{
 /**
 * @var string
 */
private $gateway = 'http://ift.tt/2tHMCb0';

/**
 * Returns PageSpeed score, page statistics, and PageSpeed formatted results for specified URL.
 *
 * @param string         $url
 * @param string         $locale
 * @param string         $strategy
 * @param optional array $extraParams
 *
 * @return array
 *
 * @throws Exception\InvalidArgumentException
 * @throws Exception\RuntimeException
 */
public function getResults($url, $locale = 'en_US', $strategy = 'desktop', array $extraParams = null)
{
    if (0 === preg_match('#http(s)?://.*#i', $url)) {
        throw new InvalidArgumentException('Invalid URL');
    }

    $client = new \Guzzle\Service\Client($this->gateway);

    /** @var $request \Guzzle\Http\Message\Request */
    $request = $client->get('runPagespeed');
    $request->getQuery()
        ->set('prettyprint', false) // reduce the response payload size
        ->set('url', $url)
        ->set('locale', $locale)
        ->set('strategy', $strategy)
        ->set('key', env('PAGESPEED_INSIGHTS_API_KEY'));

    if (isset($extraParams)) {
        $query = $request->getQuery();
        foreach ($extraParams as $key => $value) {
            $query[$key] = $value;
        }
    }

    try {
        $response = $request->send();
        $response = $response->getBody();
        $response = json_decode($response, true);

        return $response;
    } catch (\Guzzle\Http\Exception\ClientErrorResponseException $e) {
        $response = $e->getResponse();
        $response = $response->getBody();
        $response = json_decode($response);

        throw new RuntimeException($response->error->message, $response->error->code);
    }
}
}

via Chebli Mohamed