If you need to add more employees to the salary review round after you've already initiated it, you can follow this guide.
In the overview of the salary set round, you can click on "Modify Selection" at the top right.
Here you can modify your selection criteria to align with the selection you want to include in the salary setting round. At the top, you can see the already imported coworkers and how many new matches the change will result in.
Once you have adjusted the selection, you can click "Add" at the bottom left of the page.