help with asterisk, coturn and webrtc / wss webphone under aws

Hello experts
(please bid only if you have specific experience with this setup)

I've tried to configure asterisk and coturn to work around the aws natting,
normal sip softphones are working (i get two way audio)
but webrtc (using a webphone) doesn't work (it seems fine but i get no audio).

Please mind that i can't provide ssh to this server
nor sharing my desktop.


Thank you