curl_setopt_array($curl, array(
CURLOPT_URL => "https://id.wompi.sv/connect/token",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => "grant_type=client_credentials&client_id=%24%7Baccount.clientId%7D&client_secret=YOUR_CLIENT_SECRET&audience=YOUR_API_IDENTIFIER",
CURLOPT_HTTPHEADER => array(
"content-type: application/x-www-form-urlencoded"
$response = curl_exec($curl);
$err = curl_error($curl);
echo "cURL Error #:" . $err;