PlagiarismCheck will work only with “Online” submission types and of the four types of online submission types it will only work with “text entry” or “file upload.”
If you teach multiple sections of the same course you can use the same assignment but assign it with different due dates and availability dates to different sections.
PRO TIP: Add /preview to the end of URL of your google docs and slides to make a clean, read-only-view version of your work to share with students/parents.