The “API keys issue” has been discussed several times in the past (regarding other apps). The consensus was that F-Droid does not make such deals because software with “secrets” can hardly be called free. All apps on F-Droid that connect to services with API keys either have those keys in the (publicly available) source code or in the build recipe (also publicly available).
We’re definitely not going to extract the key from the official APK, that’s for sure.