Hi RICROM and welcome to SF
Take a look at my guide here since that shows how to complete the cerfa 3916 forms.
If you have a large number of accounts to declare and you are doing so still by paper returns, a separate list can still be included (it mentions such in the Fisc notes) so nothing has changed there. The online version allows you to fill in up to 99 accounts - if you have more than that… hummm.
After looking at the guide, if there are more questions, please feel free to come back and ask.