To record your meeting simply click the Record button in the top menu:
You will be prompted to begin:
When you are ready to stop recording, simply press the red Record button again:
Should you decide to start recording again, you will be prompted to choose if you want to Append (Continue from where you left off) or Overwrite (this will DELETE the previous recording time).
Recording is the same as above however you are also able to start your recording automatically when you Go On Air from the Green Room: