How can I uninstall beta on my iPad safely?

Hello all I have A 10 generation iPad which I absolutely love anyway I recently downloaded the IpadOs beta 18.1.., I went to a friend’s computer we tried twice to uninstall the beta and install the new IOS 18.0.1 unfortunately after two attempts we got error message saying firmware is corrupted..that message came from his computer about my IPad… it’s frustrating with this…I can’t even do a complete format or a reset the beta would still be there and would block any new versions..

I have to use a computer…does anyone have any ideas

thanks

[Edited by Moderator]