You can configure chats to be automatically deleted if there is no activity for a certain time.

  1. Go to Profile → three dots ⋮ → Settings.
  2. Enter Chats.
  3. Enable Delete by inactivity.
  4. Choose the time (8h, 24h, 7d, 90d).

If there is no activity during that time, the chat will be automatically deleted from your device.