If you are looking to find the total time logged on a ticket by an agent, you can make use of the 'Total Time Spent' app in the Mint UI. This app will help to track the total of all such entries logged so there is clear visibility on how much time is being spent on a ticket. This can later be used for reports and tracking an agent's productivity.
Please refer to this for more details and instructions - https://www.freshworks.com/apps/freshdesk/total_time_spent/