The senders of invoices and pay slips decide whether documents will be offered to you in Zoomit, even if you have not requested any. The messages are merely informative. You cannot switch them off; this is a standard Internet Banking service.
Of course, you are free to accept or decline the invitations from the senders to use Zoomit.
Only when you have accepted the sender in Zoomit and you have confirmed your choice, you will have access to your documents.