This warning message means that you haven't added Benefits to your company yet.
To add Benefits, please see this link: https://newaccount1614305916024.freshdesk.com/a/solutions/articles/69000300053
Once you completed adding Benefits to your company, click the profile icon in the upper-right corner of the page, go to Administration - Employee Information - edit employee
Go to Benefits Package - select Add Leave.
Tick the checkbox of the leave benefit you want to add then click Save.
The added leave will show in the Benefits Package.
Go to Employee Summary and click Save to save the changes made.
Finally, to add leave credits, please see this link:
https://newaccount1614305916024.freshdesk.com/a/solutions/articles/69000830698