使用AJAX进行g-recaptcha-response

我有一个联系表单,它将带有ajax请求的信息发送到PHP脚本.现在我想实现谷歌的“我不是一个机器人”recaptcha.

问题是,我不知道如何使用ajax传输g-recaptcha-response.
如何验证它并将结果发送到send_contactrequest_process.PHP？

<div class="kontakt-container">
  <form class="kontakt-form" id="kontakt-form" method="post">
    <input type="text" name="firstname" id="contact-form-firstname" placeholder="Vorname (erforderlich)" class="kontakt-form-input" minlength="2" required="required" data-msg="Du musst dieses Feld ausfüllen">
    <input type="text" name="lastname" id="contact-form-lastname" placeholder="Nachname (erforderlich)" class="kontakt-form-input" minlength="2" required="required" data-msg="Du musst dieses Feld ausfüllen">
    <input type="tel" name="telephone" id="contact-form-telephone" placeholder="Telefonnummer" class="kontakt-form-input">
    <input type="email" name="email" id="contact-form-email" placeholder="E-Mail (erforderlich)" class="kontakt-form-input" minlength="10" required="required" data-msg="Diese Email-Adresse ist ungültig">
    <textarea class="kontakt-form-message" id="contact-form-message" required="required" data-msg="Was möchtest du uns mitteilen?"></textarea>
    <div class="g-recaptcha" data-sitekey="MY KEY"></div>
    <div class="kontakt-form-submit" id="kontakt-form-submit">senden</div>
  </form>
  <p class="kontakt-form-success-message">Vielen Dank für Deine Nachricht.</p>
</div>

if($("#kontakt-form").valid()){

        var firstname = $('#contact-form-firstname').val(); //Validierung der Form-Daten
        var lastname = $('#contact-form-lastname').val();
        var email = $('#contact-form-email').val();
        var telephone = $('#contact-form-telephone').val();
        var message = $('#contact-form-message').val();

        $.ajax({ //AJAX request
            type: "POST",url: "../../../include/process/send_contactrequest_process.PHP",data: {firstname: firstname,lastname: lastname,email:email,telephone:telephone,message:message},success: function () {
                $('.kontakt-form-success-message').css( "display","inline" );
            },});
    }

解决方法

它只是调用这个函数grecaptcha.getResponse();
像这样 ：

if($("#kontakt-form").valid()){

    var firstname = $('#contact-form-firstname').val(); //Validierung der Form-Daten
    var lastname = $('#contact-form-lastname').val();
    var email = $('#contact-form-email').val();
    var telephone = $('#contact-form-telephone').val();
    var message = $('#contact-form-message').val();

    $.ajax({ //AJAX request
        type: "POST",data: {
          firstname: firstname,message:message,recaptcha:grecaptcha.getResponse()
        },success: function () {
            $('.kontakt-form-success-message').css( "display","inline" );
        },});
}