Dashboard Screensaver is an app that allows you to configure any web page - a dashboard, Home Assistant, Dakboard, or your favourite youtube video - as the screen saver for your Android TV. https://play.google.com/store/apps/details?id=chyzinr.webpagescreensaver
For most android TV devices simply follow the instructions and Open System Settings to set ‘Dashboard Screen Saver’ as your default screen saver. Then set the Dashboard URL to the website you want to use as the screensaver. This works for most TV, nvidia shield and miboxes. Note: this does not work for chromecast devices (eg. Google TV with chromecast), where the screensaver options have been locked down. chromecast devices require the adb method to change the screensaver
First, go to Settings > Device Preferences > About then tap several times on the Build to unlock the Developer options. You will now be able to see the unlocked Developer options menu in the Device Preferences. Locate the USB Debugging toggle and enable it. On your Android TV, go to Settings > Device Preferences > About > Status and note down the IP address.
Install ADB Tools on a PC. There’s a few different tools that will allow you to do that - I use ‘Minimal ADB’ Alternative: Install ‘Remote ADB Shell’ on an android phone.
adb connect <the IP address noted in step 1>
adb shell
settings put secure screensaver_components chyzinr.webpagescreensaver/.Screensaver
When your screensaver kicks in, it should now start the website that you’ve configured.