How to change signature of published app in Google Play Console Internal Testing?

Question

I added an application via the Google Play Console. First, I published it via Internal test and installed it on my phone, it works very stable.

I added an update to the app. But unfortunately I lost the signature that was in the first version. Then I signed the application with the new signature. Naturally, it gave me an error because I used a different signature.

How can I solve this problem? Is it possible to delete all versions and add a new application?

Thank you very much in advance for the help.