使用curl mixmax api密钥发送签名

Question

任何人都可以告诉我如何使用curl与mixmax发送电子邮件签名文本，

mixmax电子邮件发送功能已经正常工作。

$data = array('message' => array('to' => $toEmail, 'from' => 'email_id', "subject" => $subject, "html" => $content));
    $data_string = json_encode($data);

    $ch = curl_init('https://api.mixmax.com/v1/send/');
    curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
    curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_HTTPHEADER, array(
        'Content-Type: application/json',
        'X-API-Token: API key here',
        'accept-encoding: gzip, deflate',
        'Content-Length: ' . strlen($data_string))
    );
    $result = curl_exec($ch);
    if(curl_error($ch))
    {
        return false;
    }else{
        return true;
    }
    curl_close ($ch);