Hello Dear,
May I Ask, Do you have the full source code of this application?
Here, we have two problems:
1- That you did not upload a signed APK.
2- The API Target Level should be at least 28.
I can fix both problems and guarantee that the application will be uploaded successfully with no errors!
Do not hesitate to contact me, it would be awesome if we can discuss more.
I'll be waiting to hear back from you.
Best Regards!
Issam.