How to disable WebRTC in Firefox
If you’re a Firefox user, no need to install a third-party extension. Disable WebRTC directly in your browser’s settings:
Step 1: In the address bar or your Mozilla Firefox browser, type
about:config and press Enter.
Step 2: Click I accept the risk! on the warning screen that shows up.
Step 3: Type
media.peerconnection.enabled in the search bar beneath the address bar.
Step 4: Double-click the search result to change the Value column to false.