TURN integration

I did a little research WebRTC and STUN/TURN stuff a little. My question is whether it is possible to add username and password to ICE candidates. I have my own TURN server with public IP. I used several web pages for testing TURN with custom Signaling server to make sure it is working properly. And it is my understending that username and password are required for TURN server but in Wowza Streaming Engine only protocol, port and IP address can be configured for ICE candidates.