Scribbr is style agnostic. Student papers follow a variety of style guides, and Scribbr editors must be able to adapt their editing style accordingly.
We don’t expect applicants to know the ins and outs of Scribbr’s specific style of editing right away. As long as your sample edits are appropriate for an academic context (and consistent, of course), that will suffice.
If you do have questions about a specific grammar or style point, Scribbr’s Knowledge Base, the Purdue OWL, and the APA Style Blog are all excellent resources.