I want to send voice to voice chat from frontend I have a code which record the voice and create a file

I have a code of recording voice chat and create a file but i want to make a voice chatting page where user communicate with voice chat.

     function createDownloadLink(blob) {

var url = URL.createObjectURL(blob);
var au = document.createElement('audio');
var li = document.createElement('li');
var link = document.createElement('a');

//name of .wav file to use during upload and download (without 
extendion)
var filename = new Date().toISOString();

//add controls to the <audio> element
au.controls = true;
au.src = url;



   var file_data = url;

   var form_data = new FormData();

   form_data.append('file', file_data);
   form_data.append('action', 'md_support_save');



//save to disk link
link.href = url;
link.download = filename+".wav"; //download forces the browser to donwload the file using the  filename
link.innerHTML = "Save to disk";

//add the new audio element to li
li.appendChild(au);

//add the filename to the li
li.appendChild(document.createTextNode(filename+".wav "))

//add the save to disk link to li
li.appendChild(link);

//upload link
var upload = document.createElement('a');
upload.href="#";
upload.innerHTML = "Upload";
upload.addEventListener("click", function(event){
      var xhr=new XMLHttpRequest();
      xhr.onload=function(e) {
          if(this.readyState === 4) {
              console.log("Server returned: ",e.target.responseText);
          }
      };
      var fd=new FormData();
      fd.append("audio_data",blob, filename);
      xhr.open("POST","upload.php",true);
      xhr.send(fd);
})
li.appendChild(document.createTextNode (" "))//add a space in between
li.appendChild(upload)//add the upload link to li

//add the li element to the ol
recordingsList.appendChild(li);

}

Here is the code where file is downloaded in browser. I don't know how to send this file to another user from frontend while using wordpress. Can anyone suggest me what to do ?