An agent must be associated to a dialing service (and signed into it) to receive calls. This service-agent association can be mapped either by agent or by service. In either situation you can move entities from available to assigned by choosing the entity, using the left/right arrow buttons between columns, and selecting Save.
Mapping by agent is available from the Agent Mapping tab in the Agents section. To map the agents to a specific Call Center and Service:
Mapping by service is performed by selecting the agent from the Agents section and utilizing the Service Mapping tab. To map services to a specific agent:
Select one or multiple services (hold CTRL to select multiple) from the Available Service(s) column and move them to the Assigned Service(s) column.
Click the single right arrow button to move the selected services. Click the double right arrow button to move all the available services.