Signing a Ionic app in build server docker container?

Hello all, I’m a newbie who tries to build his first app. As I am confused by the information in the official docs, I hope to get some help here.

My issue is: how to make signing the app inside the build server docker container work?

I proceeded as described here:
I got as far as fdroid build --on-server com.example which builds an unsigned apk. On the way to that, I get this warning:
2022-04-18 17:45:55,882 WARNING: apksigner not found! Cannot sign or verify modern APKs
I also succeeded signing the apk that was produced inside the docker container afterwards outside the container, as described here: Signing Process | F-Droid - Free and Open Source Android App Repository

Is that the correct way to proceed and can I then just push the fdroiddata with the signed apk? Or should the signing rather be done inside the docker container?

I’d be grateful for clarification!

The buildserver should build a unsigned apk and it will be signed manully. It is the correct way and you can open an MR with your metadata. Thanks!