How does Check-in and Check.out works?

How does Check-in and Check.out works?

Hello,

I am new to zoho people, and I am trying to figure out how check-in and check-out works...

The check-in/out button is grey and when I click it I receive the following error:

" To add entry in Attendance, log time for any of your jobs"

Hope you can help me with this, regards!