cookie-forminator-submit.php

<?php

add_action( "wp_footer", function () { ?>
  <script>
    (function($) {
      $(function() {
          $(document).on("forminator:form:submit:success", function(formData) {

              let cookieName = "form_submit_success-" + $(formData.target).attr('data-form-id')

              function setCookie(name, value, days) {
                  var expires = "";
                  if (days) {
                      var date = new Date();
                      date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
                      expires = "; expires=" + date.toUTCString();
                  }
                  document.cookie = name + "=" + (value || 1) + expires + "; path=/";
              }

              setCookie(cookieName, 1, 30);

          });
      });
    })(window.jQuery);
  </script>
<?php }, 21 );