绑定输入类型提交

I have Registration.html fail, which contains registration form. The other failure is in KinveyRequester.js

function registerUser(e) {
    e.preventDefault();

    let userData = {
      username: $("#registerUsername").val(),
      password: $("#registerPassword").val()
    };
    $.ajax({
      method: "POST",
      url: kinveyBaseUrl + '/user/' + kinveyAppKey,
      headers: kinveyAppAuthHeaders,
      data: userData,
      success: registerSuccess,
      error: handleAjaxError
    });

    function registerSuccess(userInfo) {
      saveAuthInSession(userInfo);
      showInfo("User Successfully Registered");
    }

The Question is:

How can i bind and when i clicked "Register" button it runs correctly and register a user. Here is the Register.html fail

You can bind registerUser function with your submit button simply by using jQuery on() method:

$(document).ready(function() {
    $('#reg-btn').on('click', registerUser);
});

But it's better to bind on form's submit event:

$(document).ready(function() {
    $('#your-form').on('submit', registerUser);
});

but in that case you have to return false at the end of the your registerUser function in order to prevent default submit behaviour.

for example like: $('input[type="submit"]').on( 'click', registerUser() ); or with a class for the submit button like $( document ).on( 'click', '.yourSubmitClass', registerUser() );

Do not bind the submit button, instead bind the form submit Also move the inline onload:

$(function() {
  startApplication();
  $("#registerUserForm").on("submit",registerUser); 
});

Also you need a } between these:

  });
} <<<<<<<<<<
function registerSuccess(userInfo) {

Example of the submit is here https://jsfiddle.net/2bvuc6on/ since StackSnippets block submit