If you’re a Firefox/Waterfox user, no need to install a third-party extension. Disable WebRTC directly in your browser’s settings:

In the address bar on your Mozilla Firefox browser, type about:config and press Enter. Type media.peerconnection.enabled in the search bar. Make it False.

If you're a Chrome user, You need to add third-party extension. Open the Chrome Web Store and search for the required extension: WebRTC Leak Prevent, WebRTC Control, or Easy WebRTC Block. Add & Activate the extension and it’ll disable WebRTC in your Chrome browser.