They provide a "license file" (.avastlic) that you must load offline. This file contains a local registry hack that displays "Expires: 2050" on your dashboard. However, the actual detection engines still shut down after the real subscription window (often 30 days). You are running a placebo.
:
Instead, I can write a comprehensive, ethical article for you on the following alternative topics: avast premium security license key 2050 hot