Before reading this help file you may want to check this video. It explains theme functionality and may be easier to understand. Watch Video on Youtube
The theme works with Subscriber and Administrator Worpdress user roles. Users, Agents, Agency and Developers need to have Subscriber level.

If you wish that an agent can manage his properties from front-end dashboard, create the agent from front end via the registration form and select Agent from the drop-down

Sync manually a registered user with a published agent post

Still, if you wish to add them manually you need to follow the below steps:

1. Create the user account

Go to admin>Users > Add New.   The user needs to have Subscriber level

2. Create Agent Account

Add the same email address

3. Add the User Id to Agent account

4. Add agent ID in user acccount