If you as a business account customer want access to private charging stations and areas, you can contact the facility owner and request membership. You then share your unique company code with the facility owner, who can invite you as a member to their area. As a business account customer, you are still responsible for your own users and for keeping the user register up to date.
If you are a facility owner, there is a guide for how to add the company as a member in the customer portal HERE, see the heading "Members".