Check user if subscribed to my channel

API
49

I do not know what I do badly.

if (json_last_error() == JSON_ERROR_NONE) {
// el token es bueno
// vamos a obtener el usuario para el que es este token
//$ch = curl_init(‘https://api.twitch.tv/helix/subscriptions?broadcaster_id=507703972&user_id=’ . $idtwitch);
$ch = curl_init(‘https://api.twitch.tv/helix/channel_points/custom_rewards?broadcaster_id=507703972’);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
'Client-ID: ’ . CLIENT_ID,
'Authorization: Bearer ’ . $_SESSION[‘token’]->access_token
));

error:Helix did not return a single user