Question about QBI safe harbor

Hi, I am TurboTax ask me if I am eligible for the QBI safe harbor. One of the condition that I must met is Performed 250 hours or more in rental services across all properties (by you or hired workers)
I hired a management agent to do this work for me. According to some online information, they is considered as "hired workers". How should I know prove that 250 hours then? 
 
Thanks in advance