Exemplo de código PHP para solicitar token de autorização via API Pix

$curl = curl_init();

curl_setopt_array($curl, array(
CURLOPT_URL => 'https://api-pix-h.gerencianet.com.br/oauth/token',
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(
'x-client-cert-pem: {{X-Certificate-Pem}}',
'Authorization: Basic (client id e secret em base64)',
'Content-Type: application/json'
),
));

$response = curl_exec($curl);

curl_close($curl);
echo $response;