How to use Express response inside promise callback

If this question has been answered elsewhere, I apologize. I have been stuck on this issue for the past few hours. I have a simple nodejs application that accepts a message posted from the front end, calls an asynchronous service with the message, and returns the response. Below is the code:

('#btn').click(function (e) {
    var message = $('#message').val();
    $.ajax({
        method: "POST",
        url: "./api/text",
        contentType: "application/json",
        data: JSON.stringify({ text: message })
    })
    .done(function (res) {
        debugger;
        console.log('Test'); // Debugger and log never hit
        $('#msg_response').html(res);
    });
});

/////////////////////////////////////////////////////////////////////////

app.post("/api/text", function(request, response) {
  var message = request.body.text;

  var client = new Client();

  client.doSomethingAsync({
      data: message
  }, function (err, msg) {
      // Getting here, but never returning to 'done' above
      response.json(JSON.stringify(msg));
      response.end();
  });
});

The issue is that the response from the "post" request is never being received from the server. I believe it has something to do with the response being sent in the callback function because if I take the response out of the callback, everything works great. Is it possible to send the response back from an asynchronous call?

Thanks for any help.

via ABondi415