Turnitin ignores Canvas anonymous grading rules
Papers submitted to Canvas and then viewed in Turnitin will have identifying information even if anonymous grading has been enabled in the Canvas Assignment.
When an instructor sets anonymous grading for an assignment in Canvas, Canvas will prevent all graders from seeing student names. All student names are replaced with a "Student #":
When a grader opens the Turnitin report for a paper, they are redirected to the Turnitin system where the student's name will be revealed:
Reminder: Even in Canvas, anonymous grading will not be fool proof if a student includes their name within the file or in the file name. It is best to instruct your students to omit their name from within their paper and their document's file name if you are planning to do any anonymous grading in Canvas.