Your company's support solution is Freshdesk which allows you to have agents on the helpdesk, working on different functionalities of the helpdesk. You could choose to buy a number of licenses that work as seats available on the portal that can be filled by an agent.
Please go to Admin > Team > Agents. Kindly click on that to add a new agent to the portal. Once you click on the new agent button, you would be taken to a page where you could enter the details of an agent that includes name, email address, groups that one can be part of, roles that can be assigned and scope ( the level of access to the portal.)
You can add them as a full-time or as an occasional agent. Please find the difference here.
Note: Admins can add only 10 agents to their account on the Free and Trial plan.