jquery - Why multiple ajax requests in each other do not execute?

I have multiple ajax functions inside each other, but only the first ajax request is executed and I do not know why! I have added some alert fields to see how far it gets.
I am using django environment for this.
So for example when the bidnow-BTN is clicked this jquery should execute, but for some reason the after the first ajax request the page actually refreshes and adds something like
/?bidPrice=100001 to the end of the url of the page. This should not happen.

$("#bidnow-BTN").click(function () {
  var varurl = document.URL
  var itemId = varurl.split(/\//)[4]


  $.ajax({
    url: "{% url 'User ID' %} ",
    method: "GET",
    success: function (data) {
      var varurl = document.URL
      var itemId = varurl.split(/\//)[4]
      var username = data.username
      alert("Got here: " + username)

      $.ajax({

        url: "{% url 'Bidding ID' %} ",
        method: "GET",
        success: function (data) {
          alert("Does NOT reach this point")
          for (var i = 0; i < data.users.length; i++) {
            if (data.users[i].username == username) {
              var id = data.users[i].id
            }
            else {


            }
          }


          $.ajax({ // kinda checked
            url: "{% url 'List Items' %} ",
            method: "GET",
            success: function (data) {
              var varurl = document.URL
              var itemId = varurl.split(/\//)[4]

              for (var i = 0; i < data.items.length; i++) {
                if (itemId == data.items[i].id) {
                  var currentPrice = data.items[i].higestBid
                }
                else {

                }
                if (parseFloat($('#bidAmount').val()) <= currentPrice) {
                  alert("Please enter a higher amount")
                  abort()

                }

                if (parseFloat($('#bidAmount').val()) > currentPrice) {

                  var post_data = {
                    'itemId': itemId,
                    'userID': id,
                    'bid': (parseFloat($('#bidAmount').val()) || 0)
                  };


                  $.ajax({ //checked
                    url: "{% url 'Modify Bid' %} ",
                    contentType: 'application/json; charset=utf-8',
                    dataType: 'json',
                    method: "PUT",
                    data: JSON.stringify(post_data),
                    success: function (data) {
                      $('#ItemCurrentPrice').empty()
                      $('#ItemCurrentPrice').append("£" + data.highestBid)






                      $.ajax({ //checked
                        url: "{% url 'Bidding ID' %} ",
                        method: "GET",
                        success: function (data) {
                          for (var i = 0; i < data.users.length; i++) {
                            if (data.users[i].username == username) {

                              var id = data.users[i].id
                            }
                            else {

                            }
                          }
                          var post_data = {
                            'itemId': itemId,
                            'userID': id,
                            'bid': (parseFloat($('#bidAmount').val()) || 0)

                          };
                          $.ajax( //checked
                            {
                              url: "{% url 'List Bid' %} ",
                              contentType: 'application/json; charset=utf-8',
                              dataType: 'json',
                              method: "PUT",
                              data: JSON.stringify(post_data),
                              success: function (data) {


                              }
                            }) //Checked




                        }
                      })  //Checked

                    }

                  })  //Checked
                }
              }
            }
          })

        }
      })
    }
  })

})