I have the same issue. I’m doing this in a Linux container (Ubuntu 20.04 inside Ubuntu 20.04), but like matthaios-easy-bi, I’m using npm run build:android to build (as per documentation). This has worked up until 2.0, but with 2.1 it always fails due to non-existent org.webrtc. Manually running npm install prior to npm run build:android makes no difference, nor does node node_modules/react-native-webrtc/tools/downloadWebRTC.js (although it does seemingly download the package successfully).

Here’s excerpts from the build output.