Added callback for 'transport-produce'

app.js

@@ -229,7 +229,7 @@ peers.on('connection', async socket => {
     - For the router with the id callId, we make produce on producerTransport
     - Create the handler on producer at the 'transportclose' event
   */
-  socket.on('transport-produce', async ({ kind, rtpParameters, appData }) => {
+  socket.on('transport-produce', async ({ kind, rtpParameters, appData }, callback) => {
     try {
       const callId = socketDetails[socket.id];
 
@@ -257,6 +257,11 @@ peers.on('connection', async socket => {
         console.log('transport for this producer closed', callId)
         closeCall(callId);
       });
+
+      // Send back to the client the Producer's id
+      callback({
+        id: producer.id
+      });
     } catch (error) {
       console.log(`ERROR | transport-produce | callId ${socketDetails[socket.id]} | ${error.message}`);
     }