Currently, on the free plan, it's possible to manually toggle on (blue) or off (grey) the meetings which you want the notetaker bot to join.
However, if you don't want to manually use the toggle for each meeting, there are other options.
With any paid plan, the bot default joining rules in settings are unlocked. You'll be able to choose between the bot being sent to...
1) all meetings
2) internal calls only
3) external calls only
4) no meetings