Otherwise, you'll have to wait until Apple releases the public versions.
Don't get too excited.
Worth noting is the fact you can do nothing but unlock your iPhone with this feature.
Go to the Watch app General Software Update and download watchOS 7.4.
Back in March, when coronavirus began impacting Americans within the states, iPhone users discovered that by wearing a face masks Face ID was blocked from unlocking their devices forcing them to open the Passcode enter display. Otherwise, the feature won't work at all.
The Face ID and Passcode screen of the iOS Settings app activates this option. "If you are wearing a mask and have an unlocked Apple Watch on your wrist, you can unlock FaceID on your iPhone".
However, since the outbreak of the coronavirus, using Face ID has become more challenging as mask-wearing has become more common. Sadly, I'm not creative enough to think of a name like this for my iPhone. It will then check if the owner's Apple Watch is nearby (using Bluetooth), on the owner's wrist (by detecting a heartbeat), and unlocked. A button to lock the iPhone will also appear underneath that notification. It's a trend that we already saw with Face ID, which blew away the two-dimensional facial recognition systems that came before, which could often be fooled with a photograph, and there's every reason to believe that Apple is going to do the same with its new in-display Touch ID, and we already know it's working on some pretty cool ideas. This may very well be achieved by means of using Machine Learning to assist analyze users' spending and decide what, if any, steps may very well be taken to enhance the person's monetary state of affairs. And, if you're feeling up to the challenge, there's also a hack you can try: Cover half your mouth with a mask and scan an alternate Face ID appearance.
Again, this official Apple Watch / Face ID feature isn't available for everyone just yet - it's only available as a developer beta.