Yes, you can keep recording a session even after the note has been generated.
Open the note and click the Transcript tab.
Click Resume Session.
Record any additional audio. It's added as context, and your note is fully regenerated to include it.
đĄ Because the note is fully regenerated, any manual edits you made beforehand may be replaced. Make your edits after you've finished adding audio. See the article "Reviewing your generated note".