As a supervisor, you have the right to require an employee to work overtime. However, you CANNOT require an employee to accept comp time. Under the regulations the employee must have the choice to either be paid overtime or given comp time. You can ask an employee to work overtime and tell them that you can only offer comp time for the additional hours. In this case, the employee can either accept that or not. If they don’t accept it and it’s critical that you have the employee work overtime, then you will need to pay the employee overtime.