If you have connected accounts of several administrators in SMMplanner cabinet, who manage one page/group, you can choose on behalf of which administrator the posting will go. To do this, go to the Projects section on the left side menu and remove the editing of the desired page.
You will see a list of accounts that are allowed to publish on this page via SMMplanner.
By default, posting goes through the first administrator. If for some reason posting through it is not possible (the account's posting rights to this page have been revoked, account authorization on the service has been terminated, etc.), then posting will go through the second administrator in the list of administrators, and so on.