Phone settings

Enable watch face lock in Wear Cloud Editor

► Tap lock to lock / unlock

► Long tap lock to turn auto-lock on / off

AUTO LOCK
The screen will automatically lock when it dims to ambient mode
► Tap lock bubble to unlock temporarily
► Long press lock bubble to disable auto-lock

More on active and inactive watch-face modes: Watch face mode

Watch settings

Enabling the lock bubble in the settings on the watch: Favorite Cloud → “Touch-lock bubble”

Assigning touch lock to hardware button

On the watch: Shortcuts → Choose button to assign

→ Select action “Lock/Unlock screen touch”

On the phone: set in the section “Shortcuts”:

This video shows how to assign actions to the long press of the main button: