I can't update my iPhone

Can you post a screenshot of the whole screen, it could reveal why you aren't able to update.

Make sure you:

• Are using a WiFi connection (not a hotspot).

• You have an active cell signal (You need both WiFi and cellular service to perform the upgrade).

• Are not using a VPN connection.

• Have your battery charged at least 50%. Better yet, keep it plugged in during the update.

• Do not have power save mode turned on.

• Do not have a beta version installed.

• You have at least 10 gigs of storage available.

Click on this link on what to do if you can't update your phone -

If your iPhone or iPad won't update – Apple Support (UK)

Do you have enough free storage on the iPhone to do the update?

Also, do you have cellular reception, and cell data turned on? You want the phone to do the bulk of the download over WiFi, but I've seen some posts claiming that certain updates require cell data to be turned on as well.