If your time sheet page is empty and have ensured all the pre-requisites have been met, this is an indication that WorkGuru has not been able to match your WorkGuru staff to the Employees in Xero.
Most common reason for that is one of the following:
1. Staff Full Name / email doesn't match between WorkGuru and Xero
2. The draft pay run that's open is for the wrong employee type (e.g. Salary vs wages)