To add an agent, first of all, please make sure you have the permission to do so:
Then,
Step 1: Open the client’s application detail page by clicking on the application under which you want to add the agent.
Step 2: Scroll down and select the “+” icon beside the super agent if you want to add the super agent and select the “+” icon beside the subagent if you want to add the subagent.
Step 3: Select the agent from the dropdown.
The agents are now added.