PSU uses Canvas LMS.  We can use Turnitin at LTI (linked technologies), allowing originality checking and mark-up for written work submitted through Canvas courses.  I appreciate the added benefits of having Turnitin in our Canvas courses. 

Recently I began co-teaching a course.  I found that having two teachers is possible in Canvas but not in Turnitin.  Our online community, along with Turnitin help desk, noted that Turnitin courses have only one instructor (though a master course can have a teacher and one or more section TAs).  This is not necessarily a problem needing a solution for co-teachers using canvas.

From within a Canvas course, instructors create a writing assignment using the submission type 'external tool' and select Canvas LTI for uploads (if and when it's an option).  Then 'push' that assignment into Turnitin by selecting the 'submit assignment in a new window' button.  The assignment deadline should be established in a linked/new Turnitin course (creating an assignments folder).  Instructors can add students into the course (as a set) or allow each student to self-enroll in the Turnitin course by submitting a first course assignment. 

In this situation, neither students nor instructors need to go into 'Turnitin.com' (or, in my case, Turnitin.psu.edu) to upload a document to Turnitin.  Simply use Canvas for all assignments.  If any person in the course wants to see more detail that is based on Turnitin (e.g. originality score details or mark-up), they can select the Canvas-based link for a particular assignment uploaded through Canvas.