You can quickly and easily enable lock screen notifications in ChromeOS 77+ with a simple flag. Once enabled you can get notifications on your lock screen much like your mobile device.

• To enable just add the following flag to your Chrome Browser address bar
• chrome://flags/#enable-lock-screen-notification

• Now click on Restart Now in the bottom right corner
• You should now start seeing notifications on your lock screen

Source: Kodi Addons