Why won’t my iPhone updates download?
Why won’t my updates download?
[Re-Titled by Moderator]
iPhone X, iOS 14
Question marked as
No beta profile, Wi-Fi or wired to a computer, no add-on VPN client apps, and sufficient free storage, are all requirements.
Update your iPhone or iPad - Apple Support
How to uninstall iOS or iPadOS beta software - Apple Support
If that fails, use a computer and a cable, as described in that first link.