You can activate 'Ask for Reason' if you want to know why someone is calling before you answer the call.
Simply activate 'Ask for Reason' for your number on manage.yodel.io and either enter a text which Yodel reads out or upload an mp3 file with your own recording.
Make sure that if Yodel reads out the text, it should be in the same language as the selected 'voice for announcements' and the 'transcription language'. Otherwise Yodel is not able to pronounce the text properly.
Once the feature is activated, Yodel will read out your message to the caller and transcribes it in your Slack channels.