VPN app not found

I have the Avast VPN app on my Android TV, but after resetting the
device it was previously installed on, the app can no longer be found in
the Android TV Play Store. How is this possible?

And when I search for the app via the Play Store on my PC, the options to install it—for example, on the TV—are not available, and KPN has told me they are not blocking the app.