Advertising cabinet of a Business manager
Each business manager can create 1 advertising cabinet according to the standard. But after a certain amount of time (always in different ways) and the ebb of advertising, Facebook will give you the opportunity to create 4 more advertising cabinets.
If you use the BM for a long time, then perhaps Facebook will be kind to you and will allow you to create 20 more advertising cabinets - but this is usually very rare.
In the advertising cabinet, all the main actions related to advertising on Facebook are carried out.