LDAP users won't automatically be populated in the Access Server. Access Server just uses LDAP as a source for authentication.
Access Server's User Permissions screen can contain users and settings. If the username matches that which is known in the authentication backend, the properties set under User Permissions will be applied. You can do this manually or you can use a post-auth script that adds each user as they log on. You can for example query the LDAP server which group membership a user has, and based on that, map it to a group in Access Server. Then the User Permissions screen is populated with users as they log on.
If you put in a request at our support ticket system (
www.openvpn.net > sign in > support) you can get a document sent to you that explains how this works with the post-auth script, complete with a ready-made script that you need only adjust to your needs.