The Blacklist or Prompt To Record.
As of version 18.104.22.168, Parrot has a feature to blacklist phone numbers. This ensures that they are never recorded.
Your basic voicemail number (if accessed from the phone app at the top left) is added to the blacklist by default.
You can add a number to the blacklist in Settings -> Phone Calls -> Blacklist.
Prompt To Record
You can choose to only record calls on demand rather than automatically by going to Settings -> Phone Calls -> Record Call When Connected and setting it to Prompt.