sim estou usando cURL.
//Desenvolvido pela Consultoria Técnica da Efí
$config = [
"client_id" => "YOUR-CLIENT-ID",
"client_secret" => "YOUR-CLIENT-SECRET"
];
$autorizacao = base64_encode($config["client_id"] . ":" . $config["client_secret"]);
$curl = curl_init();
curl_setopt_array($curl, array(
CURLOPT_URL => 'https://cobrancas-h.api.efipay.com.br/v1/authorize',
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => '',
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 0,
CURLOPT_FOLLOWLOCATION => true,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => 'POST',
CURLOPT_POSTFIELDS =>'{ "grant_type": "client_credentials"}',
CURLOPT_HTTPHEADER => array(
"Authorization: Basic $autorizacao",
"Content-Type: application/json"
),
));
$response = curl_exec($curl);
curl_close($curl);
echo "";
echo $response;
echo "
";
?>
com as devidas alterações no client_id e client_secret.