Why this error 😔“To update the software on your Apple Watch, you first need to update the software on your iPhone”

Hi

Although you are up to date on iOS 14.8 you are not upgraded to iOS 15

watchOS 8 compatibility.

• watchOS 8 requires iPhone 6s or later with iOS 15 or later and one of the following Apple Watch models:
• Apple Watch Series 3
• Apple Watch Series 4
• Apple Watch Series 5
• Apple Watch SE
• Apple Watch Series 6
• Apple Watch Series 7

per https://www.apple.com/ie/watchos/watchos-8/

Tap on upgrade to ios15 at the bottom of the screen.