how to update iOS on Mac

The below ONLY APPLIES to MacOS for computers and Not to iDevices using iOS

The Age of this computer will Govern what newer version of macOS it will Qualify to install. Use About this Mac from the Apple Icon on Desktop - the required Information will be there.

With the above information in-hand - follow this How to get old versions of macOS and verify what version this computer Qualifies to install. Make sure to use Only Safari to commence the download as Others may not work. Safari will open a redirect and open the Apple Store where you can commence the download. If an error message appears, that is probably because one is using another Browser.

Suggest using Go64 to find 32 bit application before attempting the upGrade. Some or many of the Application already installed may required update or upGrades to 64 Bit Versions.

Make a Time Machine Backup Before attempting. Notation - Mojave is the Last version to support 32 bit applications / extensions and Drivers. Catalina & Big Sur support 64 bit and there is no workaround.

Are there any AntiVirus, Disk Cleaner, Optimizers, Un-installers, etc installed which should be removed as per Developers Instructions. They are useless, unneeded, cause havoc and interfere with the normal operation of the OS and may even Corrupt the OS requiring a Reinstallation

iOS only runs on iPhones, and iPads. Updating its OS, is discussed here:

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

Keep in mind, if you have a computer, it is best to sync it with the computer first and run a backup to the computer first before upgrading the OS of either or.

https://support.apple.com/en-us/HT203977

Mac OS runs on Macs like your MacBook Pro. If it is a 2020 Model, you can't be running 10.12.6.

If you are running an earlier model, here are the available upgrades:

10.13 High Sierra, 10.14 Mojave, 10.15 Catalina, 11.0 Big Sur.

Are you talking about macOS, which runs on the Mac, or iOS, which runs on an iPhone or iPad?