JSFiddle - React, Tailwind, and code Playground

HTML

<form name="action" id="action" action="action_page.php" method="post">
   <input type="text" id="fname" name="fname"><br><br>
   <input type="text" id="lname" name="lname"><br><br>
   <input type="button" id="submit_button" value="Submit">
</form>

JavaScript

$('#submit_button').on('click', function(e) {

  //ok, so do your ajax call
  $.ajax({
    url:'myurl.php',
    type:'GET',
    success: function(data) {
      $('form').submit();//finally submit
    },
    error: function(xhr, status, error) {
      alert('Ajax error');
    }
  });
  
});