Why does CCFOUND take authorization from the author to issue invoices on behalf of the author?

Hi, what does this consent mean: "I hereby authorize CCFOUND Sp. z o.o. Sp. K. (hereinafter "Seller") to issue a relevant document (invoice or invoice, including VAT invoice) on my behalf for the benefit of the Seller, based on which settlement for Products sold in the Market will take place with me. At the same time, I declare that I undertake to include in the settlement the document issued in accordance with the above (including the posting of the document in the scope of my business activity)" - Will CCFOUND issue an invoice on behalf of the author based on the authorization? But the author has his own accounting system in which he issues invoices. After all, it is not possible to add outgoing invoices in such a system from the outside, because it is this system that issues such invoices. It has its own numbering rules etc. How is this supposed to work? Why can't we just inform the author how much the invoice should be issued for?