This topic has been covered before on the old Reddit site and is indeed due to API changes. Nothing wrong with the game at all and it works fine on Android 13. Just Google screwing with people. Much like Micro$oft forcing people to stop using DOS.

https://www.reddit.com/r/PixelDungeon/comments/15owmbi/vanilla_pd_taken_off_the_ios_app_store/

Thanks to this wonderful thing called a search engine it doesn’t take much effort to find the original PD homepage from where the game can be downloaded for free.

https://watabou.itch.io/pixel-dungeon

https://github.com/watabou/pixel-dungeon/releases

https://apkcombo.com/pixel-dungeon/com.watabou.pixeldungeon/