$endpoint   = "https://my.sparrowhost.in/modules/addons/DomainsReseller/api/index.php";
$action     = "/order/domains/renew";
$params     = [
    "domain"    => "example.com",
    "regperiod" => "3",
    "addons"    => [
        "dnsmanagement"     => 0,
        "emailforwarding"   => 1,
        "idprotection"      => 1,
    ]
];
$headers = [
    "username: email@example.com",
    "token: ". base64_encode(hash_hmac("sha256", "1234567890QWERTYUIOPASDFGHJKLZXCVBNM", "email@example.com:".gmdate("y-m-d H")))
];

$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, "{$endpoint}{$action}");
curl_setopt($curl, CURLOPT_POST, true);
curl_setopt($curl, CURLOPT_POSTFIELDS, http_build_query($params));
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, true);
curl_setopt($curl, CURLOPT_HTTPHEADER, $headers);

$response = curl_exec($curl);
curl_close($curl);