The Audit Log has been available in all versions of Skyline since 2018.
If audit logging is not currently enabled in your Skyline document you can turn it on by first using the menu item:
View > Other Grids > Audit Log
and then checking the checkbox that says "Enable audit logging".
There is some more documentation about the audit log here:
https://skyline.ms/wiki/home/software/Skyline/page.view?name=audit-logging
-- Nick