

That depends on where you got the APK from
- the playstore apk only supports FCM
- the standalone, hidden (you only find it via search engines), apk on their website also supports websocket
- Twinhelix Signal-FOSS only supports websocket
- molly also supports blobfree FCM and UnifiedPush
But note that UnifiedPush is not supported by signal, so you need to register a fake device on a server running MollySocket. Which is very much additional attack surface and only worth it if you really rarely use signal



They dont want to give control to platforms and their policies or update frequencies or some nonsense. Meanwhile they love Google