Pairing my watch
The back of my phone shattered so I got it replaced, phone restored to my latest back up. I have not been successful on on pairing my watch since.
Question marked as
Put your watch on its charger and keep it there until you complete these steps. (select the watch OS version)
Erase Apple Watch – Apple Support (UK)
Erasing all content and settings this way erases all media, data, and settings from your Apple Watch, but it does not remove Activation Lock if it has one.
Or as it is already under your iCloud account you can erase and remove it from your account in Find My or https://icloud.com/find .
Wait for the process to finish, then set up your Apple Watch again. Set up your Apple Watch – Apple Support