Finally I've found an answer, so I post it here. Recently BridgeBase blog posted an article explaining everything; in particular, the answer to my question: <The first thing to do, before anything else, when trying to create a tournament with an entry fee and associated with an organization code is to click the Entries tab and type the code you were given in the “Type” field.> So the code has to be sent to you by BBO. I link you the full article: https://blog.bridgebase.com/2020/04/02/the-virtual-club-manager-manual/ Thank you all :) G.