To send one meeting, open it, tap Share, then WhatsApp for the minutes as a plain message, or PDF then Share PDF for the document (how).
Get them automatically
Connect WhatsApp in Settings and switch on Send my minutes on WhatsApp when they're ready (WhatsApp messages from MeetNotes).
Send audio the other way
Forward a voice note or an audio file to MeetNotes on WhatsApp and the notes come back in the same chat (MeetNotes in WhatsApp).
