Well, I have tried a lot of JS codes to post one form with multiple data [2 Files & 1 textarea] and they didn't work well.
But How to send non-empty form data to PHP using AJAX?
<form method="post" enctype="multipart/form-data">
  <textarea id="acas"></textarea>
  <input id="uimage" type="file" name="image" accept=".png,.jpg,.gif"/>
  <input id="uaudio" type="file" name="audio" accept=".mp3"/>
  <input id="armes" style="display: none;" name="send" type="submit"/>
</form>
By default I use this JS code below to submit form, But it reloads page:
$("#acas").on('keydown', function(e) {
    if (e.key == "Enter") { 
      if (e.shiftKey) {
      } else {
        e.preventDefault();
        $("#armes").click();
      }
    }
});
 
     
    