Am unable to update my iPhone 6s to 14.5 version

Do you really have a 6s or is it a 6. An iPhone 6 cannot update past iOS 12.5.3.

Please read through the user tip below for possible causes.

https://discussions.apple.com/docs/DOC-250003031

Yes it’s a 6s

What is the existing version of iOS?

What happens when you attempt to update?

Any error messages?

Existing version is 14.2

Message: unable to check for update

Plenty of storage: using 33g of 128 avail