Guzzle send request : error 7 Failed to connect to “URL : connection refused

I’m using Guzzle within my app to make a request to /connect/token/ to get a token but I got this error :

cURL error 7: Failed to connect to <url> : Connection refused

there is my code :

           $this->client = new Client([
            'base_uri' => $this->settings['apiUrl']
        ]);
        $headers = [
            'Content-Type' => 'application/x-www-form-urlencoded'
        ];
        $options = [
            'form_params' => [
                'grant_type' => 'client_credentials',
                'client_id' => 'myclientId',
                'client_secret' => 'myclientsecret',
                'scope' => 'my.api.website'
            ]];

        try {
            $response = $this->client->request('POST', 'connect/token', $options);
            var_dump($response->getStatusCode());
            var_dump($response->getBody());
        } catch (RequestException $e) {
            var_dump(Message::toString($e->getRequest()));
            if ($e->hasResponse()) {
                var_dump(Message::toString($e->getResponse()));
            }
        }

There is the response of the catch :

"POST /connect/token HTTP/1.1
Content-Length: 166
User-Agent: GuzzleHttp/6.5.5 curl/7.74.0 PHP/7.4.32
Content-Type: application/x-www-form-urlencoded
Host: MyBaseUrl

grant_type=client_credentials&client_id=rMyClientId&client_secret=MyClientSecret&scope=my.api.website"

I got this from my working postman request, I get the code with the “code” tab on postman

Someone have an idea about this error ? thanks