1. Go to Settings in the left-side panel.
  2. Select Organization & Team.
  3. Click Invite a New Team Member.
  4. Enter a name, email, phone number (optional) and choose the agent’s role.
  5. Click Add New Agent to save.
  6. The agent will then receive an email with an invite.
  7. Finally, don't forget to assign the agent to queues.

An agent can also be added by clicking "+" next to Team List in the bottom of the left-side panel.