You can receive beta (test) releases by switching the update channel to Test.
Open the Dev page of your Volumio device:
Type the local IP / address in your browser and add /dev at the end (i.e: volumio.local/dev OR 192.168.x.x/dev)
In the Update Channel Selection section, use the dropdown to select:
Test → to receive beta/test updates
Stable → to receive official stable updates
Go back to the main Volumio UI.
You are now ready to download beta test updates from SYSTEM MENU
Note: If you don’t want automatic beta builds anymore, go back to /dev and switch the channel to Stable.