Add the numbers your agency gave you, either by pasting them or with your publisher prefix, and the studio lists every number in the block. Then give each format its number: it goes on the copyright page and into the files the next time you build.
Each number moves through four states:
- Available: yours, not on a book yet.
- Assigned: on a format in the studio.
- Registered: you've filled in its record with the agency.
- Published: the book is on sale with it.
The studio never registers numbers for you. It keeps your ledger, and the agency guide on each edition shows what to enter in the agency's form.