Hi @gabrielle_gambo ...
This may depend on how your school has Turnitin set up. Ultimately, you may need to check with your instructor on how to submit an assignment via Turnitin. There are two ways I'm familiar with...via the Turnitin website (check out the Guides here: Quick Start Guide - Guides.turnitin.com and/or this video Submitting to an assignment - YouTube) or via the Turnitin/Canvas integration that your school and/or your instructor has set up in your Canvas course.
The screen shots in these videos may have been updated since the videos were created, but the process should be generally the same...
Canvas + Turnitin LTI From a Student's Perspective - YouTube
How to Submit an Assignment to Turnitin in Canvas for Students - YouTube
How to Submit a TurnItIn Assignment in Canvas - YouTube
You would want to check with your instructor on the specifics of how you should submit your assignment via Turnitin.
Hope this helps, Gabrielle.
