How do I refill a student's empty pack?

From the student's pack card in the tenant panel: sell a new pack, pick the number of sessions, and the invoice is issued from there. For monthly packs there is nothing to touch at all — the next period's renewal is issued on the school's issue date.

A pack that is still active cannot be overwritten by a new one; the system refuses and says the student still holds a running pack in that class. The only thing allowed is a new pack replacing one that is empty, expired, or absent.