Show unpaid O/T

Hi there! I am using this app to help me maintain boundaries with my salaried job. I find myself working extra hours often with no additional pay because I feel obligated to get things done, however that’s just the nature of my job. Would it be possible to somehow differentiate in how much work I do for free? Not technically “overtime” but if I work an hour extra, show me that i reduced my hourly rate to a smaller number or show me how much work I did for free?