In your Preferences, you can set different automations for tl;dv to:
Record all meetings on my calendar, even if I don't join them
Record only meetings on my calendar that I join (only available with the Chrome Extension)
Don’t record any meetings automatically
When you choose to record automatically you can choose between:
All meetings - all of your meetings, regardless of who is present.
Internal meetings - where all participants share the same email domain as you.
External meetings - where at least one participant has a different email domain.
It is not possible to establish other criteria for tl;dv to enter or to ignore certain meeting.
Regardless of your automation choices, the tl;dv bot will always need to be manually admitted into the meeting room. You can also remove tl;dv from the meeting at any point in time (see here how to stop recording).