How to trigger a change on button click

How to trigger a change on button click

I want to update a dropdownlist when another button is click by calling trigger but getting an error. Below is my code any help will be appreciated  

  2. $("#btnReplace").click(function () {
  3.  
  4. const oldPersonId = $('#OldbuttonId').val();
  5. const newPersonId = $('#newPersonID').val();
  6. var button = this;
  7. $.ajax({
  8. method: "POST",
  9. url: "@Url.Action("Replaced", "NewReplacement")",
  10. data: { OldId: oldPersonId, NewId: newPersonId},
  11. success: function (response) {
  13. $('#cdrl-load-text', button).html('Saved!');
  14. if (response != null && response.success) {
  15. alert(response.message);
  16. } else
  17. {
  18. alert(message);
  19. }
  20. debugger;
  21. $("#OldbuttonId").val().trigger('change');
  23. },

  25. error: function (xhr) {
  26. alert('Error: No Replaced happened.');
  27. }
  28. });

  30. });