If an assignment has been set up in Canvas as a Turnitin assignment, you can attach a Turnitin rubric to the assignment. You can use the rubric to evaluate the students’ work based on the defined criteria and scales. There are four Turnitin rubric types. Of the four, the qualitative rubric is used solely to provide feedback. You cannot apply the qualitative rubric to grade students’ submitted work.

Read more on Turnitin Guides:
Rubrics and Grading Forms
Attaching a Rubric Scorecard in Feedback Studio

Read more on Canvas Community:
How do I create a Turnitin assignment?
How do I change Turnitin settings for an assignment?