Yes, any course using this software should include a statement in the syllabus. You may use or adapt the following:
“Your instructor may ask you to submit one or more of your writing assignments to the Turnitin plagiarism prevention service via Canvas (do not submit directly to the Turnitin website). Your assignment content will be checked against Internet sources, academic journal articles, and the papers of other OSU students, for common or borrowed content. Turnitin generates a report that highlights any potentially unoriginal text in your paper. Papers that you submit through Turnitin for this class or any class will be added to the OSU Turnitin database and may be checked against other OSU paper submissions. You will retain all rights to your written work."