A few more steps...
watchOS 7 beta profile has started downloading.
Make sure you open BetaProfiles.com in Safari browser and your pairing device has been updated to iOS 14.
You will see the following prompt:
Tap Allow from the popup
Then follow the prompts to install configuration beta in Settings app and restart your device.
Make sure your Apple Watch is unlocked during installation.
After your device has restarted, you can get beta update in Watch app - General - Software Update.