It seems F-droid version tries to download bootstrap-arm.zip from a folder which only contains bootstrap-aarch64.zip (https://nix-on-droid.unboiled.info/bootstrap-release-22.11)

F-droid should be avoided when you can get an apk release directly from the developer or the Google Play Store. Obtanium is great for managing this.

https://github.com/ImranR98/Obtainium https://privsec.dev/posts/android/f-droid-security-issues/