I tried to update iPad 6 to iOS 14.4. It seems to have downloaded, but is stuck onn “preparing update” How to fix this?

I tried to update iPad Air2 to iOS 14.4. It seems to have downloaded but is stuck on “preparing update”. Onetip said to delete it and try again. But it does not appear under “General: iPad storage” — so I can’t delete it. Any other tips? Should I reboot? (This all started when my iPad refused to recognize any touch, so I hard rebooted— and one of the tips for that problem was to make sure all updates were installed . So I tried to install the 14.4 - which is still “preparing update”.