Greetings @Kirkland_Pheu 
Account manager means that you will have your own person who will be handling your requests and will provide any support that you need. If you have any further questions regarding the Enterprise plans, please contact our Support Team at https://help.elfsight.com/?contact=1. They’ll be happy to help 
As for the sharing the account access with your clients, we are working on this feature. You can keep an eye on it here - Agency Account.