Originality reports are now available for Google Slides files when used in Google Classroom (previously it was just available in Google Docs). Click here for the announcement from Google.
A few brief reminders about originality reports is that you (as the teacher) can turn on 5 reports per class. Also, students can run 3 reports prior to handing the assignment in. Please click here for more information from Google.
Embedded below is a 2 minute and 2 second YouTube tutorial showing originality reports from a teacher and student point-of-view.