From APK to AAB

[Anke]

@Frank_Harr

I have an app that I uploaded as an *.apk forever and a day ago. I'd like to upload a new app and in order to do that, it has to be an *.aab.

No.

See also here:

How to upload and publish an app in the Play Store → AAB or APK

If you want to upload and publish an app in the Play Store, the following should be observed: Apps that were published in the Play Store before Aug 1, 2021 can still be uploaded as APKs in the Play Developer Console (even after Nov 2021) and therefore do not need to switch to Google App Signing (which simplifies it). Apps that were published in the Play Store after July 31, 2021 must use AABs and also Google App Signing. To test such apps in advance, you should always have an APK generated…