My phone will not update. I cannot get any email

My phone will not update

Depending on what type of iPhone you use.

If your iPhone is eligible for an update, you can check by reading this Apple article:

iPhone models compatible with iOS 15

https://support.apple.com/en-gb/guide/iphone/iphe3fa5df43/ios

At the top left you can select the correct iOS.

Then go to: Settings -> General -> Software Update.

You need about 7 GB device storage.

Turn Hotspot & VPN Off.

I cannot get any email

Do you get any error message?

Then do the update -> go to: Settings -> General -> Software Update.