Are you trying to verify the Tails update or the Monero GUI update? For Tails it is a bit harder, there is an article on why they stopped offering instructions to verify. But it is rare to have to manually update if you already have an install on a USB stick. For Monero GUI Wallet, there is a "Verify" section on the Downloads page on getmonero.org: http://monerotoruzizulg5ttgat2emf4d6fbmiea25detrmmy7erypseyteyd.onion/downloads/index.html In the Verify section there is a hidden area with the hashes that can be used to verify the download, you'll need to click on "Show hashes to verify your download". Above the hash list you'll see a few links on how to verify the downloads. Good luck!