downgrade ios

If you are using a Beta version then you can use the instructions in the follow link to move from the Beta version to the official release version but the official release version is not iOS 14.8. The official release version is iOS 15.1.x. ➔  How to uninstall iOS beta software - Apple Support

If you are using the official release version of iOS 15.x.x then you are not going to be able to downgrade.

Axel F.

Apple does not allow downgrading iOS versions. This is not supported.

Axel F.

No, because it's no longer available. If you install a beta you either keep using the beta, or you revert to the most recent release candidate.

[Edited by Moderator]