Terceiro exemplo de auth

auth3.php

curl_setopt_array($curl, array(
    CURLOPT_URL => "https://apic1.hml.stelo.com.br/",
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_ENCODING => "utf-8",
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_TIMEOUT => 30,
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
    CURLOPT_CUSTOMREQUEST => "POST",
    CURLOPT_HTTPHEADER => array(
        "authorization: Basic Y2Y4ZGI2ZmU2MWJjMWVmZWJjNmFlNGY1YWI0YWY2MGM6ZjUzOGI3M2ExMWVhYzQ5ODI3ZjZkYTY3OGU4NTlmYTc=",
        "cache-control: no-cache",
    ),
));

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
    echo "cURL Error #:" . $err;
} else {
    echo $response;
}