This message let's you know that you have no salary details set for the employees listed.
Timesheets will still be exported this employee, however they will all be transferred at the employees Ordinary Earnings Rate that is set in Xero.
For employees that work weekends or are entitled to over time or penalty rates, this may not be the desired outcome.
For information on how to setup salary details, please read the articles here: https://support.urhere.com.au/en/collections/19526915-employee-wages