Doing something with jQuery after form successfully submitted

Doing something with jQuery after form successfully submitted

I have a form modal on a Bootstrap 4 page and want to display a success message in the modal after the form is successfully submitted, but my function is firing before validation is completed. Is it possible to plug in my post-validation jQuery in here somewhere?
  2. (function() {
  3.   'use strict';
  4.   window.addEventListener('load', function() {
  5. var forms = document.getElementsByClassName('needs-validation');
  6. var validation = Array.prototype.filter.call(forms, function(form) {
  7.   form.addEventListener('submit', function(event) {
  8. if (form.checkValidity() === false) {
  9.   event.preventDefault();
  10.   event.stopPropagation();
  11. }
  12. form.classList.add('was-validated');
  13.                       }, false);
  14. });
  15.   }, false);
  16. })();