How do I update my iOS version 13.7 to 14.5

If you had the iOS 13 beta on your phone you must delete the beta profile and restart your phone - if you go to Settings>General>Software Update and it says that your phone is up to date with iOS 13.7 this is the problem.

Read this support article: How to uninstall iOS beta software - Apple Support

Regards

Giulio

Start here: https://support.apple.com/en-us/HT204204