Can anyone help with a Doge wallet backup question?

I had a wallet with about 1100 Doge coins, not much, but it's free money to me. It was on an android phone, and when I ran a backup, I got a .bak file that no other wallet seems to accept. Moved to a new phone and couldn't find a new wallet app that accepted the .bak file.

I tried a Linux wallet and nothing worked there either.

Any suggestions on how to use this backup? Or have all the Doges ran away?

No, I will not send you the file.