The Android Messages webpage has gone live already. However, the feature hasn’t seem to hit my Messages app yet. It’s likely Google will roll out the feature to the wider Messages userbase over the next couple of days.
A new update to the Android Messages app, version 3.3.043, is also rolling out via the Play Store. Users will need to install this update before they’re able to link their smartphone app to the new web client.
To get the Messages on web to work: launch the update Android Messages app, tap on the menu icon and then select “Messages for web.” Following that, a QR code scanner will appear and then head to the Messages for web page on a desktop browser and scan the QR code. If the user doesn’t choose the “remember this computer” option, it’ll require the user to scan the QR each time.