My apple watch is not updating the latest update

If the update won't start, open the Watch app on your iPhone, tap General > Usage > Software Update, then delete the update file. After you delete the file, try to download and install watchOS again. Learn what to do if you see 'Cannot Install Update' when updating Apple Watch.

Update your Apple Watch

Do you see any error messages when trying to update your Apple Watch? ... like "Cannot Install Update"

Ref: If you don’t have enough space to update your Apple Watch - Apple Support

Is your Apple Watch connected to charger and battery is more than 50%?