Register domain

$endpoint = "https://www.whogohost.com/host/modules/addons/DomainsReseller/api/index.php";
$action = "/order/domains/register";
$params = [
    "domain" => "example.com",
    "regperiod" => "1",
    "nameservers" => [
        "ns1" => "nsa.whogohost.com",
        "ns2" => "nsb.whogohost.com",
    ],
    "contacts" => [
        "registrant" => [
            "firstname" => "example",
            "lastname" => "testing",
            "fullname" => "example testing",
            "companyname" => "textmachine",
            "email" => "exam@gmail.com",
            "address1" => "4 office",
            "address2" => "",
            "city" => "Lag",
            "state" => "Lagos",
            "zipcode" => "110001",
            "country" => "Nigeria",
            "phonenumber" => "+234.812345678"
        ],
        "tech" => [
            "firstname" => "example",
            "lastname" => "testing",
            "fullname" => "example testing",
            "companyname" => "textmachine",
            "email" => "exam@gmail.com",
            "address1" => "4 office",
            "address2" => "",
            "city" => "Lag",
            "state" => "Lagos",
            "zipcode" => "110001",
            "country" => "Nigeria",
            "phonenumber" => "+234.87546898"
        ],
        "billing" => [
            "firstname" => "example",
            "lastname" => "testing",
            "fullname" => "example testing",
            "companyname" => "textmachine",
            "email" => "exam@gmail.com",
            "address1" => "4 office",
            "address2" => "",
            "city" => "Lag",
            "state" => "Lagos",
            "zipcode" => "110001",
            "country" => "Nigeria",
            "phonenumber" => "+234.812345678"
        ],
        "admin" => [
            "firstname" => "example",
            "lastname" => "testing",
            "fullname" => "example testing",
            "companyname" => "textmachine",
            "email" => "exam@gmail.com",
            "address1" => "4 office",
            "address2" => "",
            "city" => "Lag",
            "state" => "Lagos",
            "zipcode" => "110001",
            "country" => "Nigeria",
            "phonenumber" => "+234.812345678"
        ],
    ]
];
$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);