1. Open 1Password Mac app
2. Go to Preferences > Security > Apple Watch (there's also option to enable Touch ID) and enable it
Make sure you have your browser 1Password plugin updated to the latest version.
When you click on the locked 1Password icon in the browser, you get the "Double click to approve" alert on your Apple Watch. You double click the side button on your watch and 1Password in your browser is now unlocked. This also works the same way with Touch ID. Hope that helps. Cheers.
Can you point me to where this gets set up? I'd love to do this.