Hey Tomm,
You need to use the newRows object that is available in your table. However, most likely you will need to use a separate query than the one you are using for the bulk update.
Here's an example from another user. Or this one that actually uses the same Upsert query for both edit changes and new rows.
I hope this helps!
P.S. Sorry for not getting back to your DM yet, have been extremely busy lately