Class IDs usually expire after the semester ends.
Depending on whether you have an existing account, the process varies slightly: Where can I find the class ID and class enrollment key? turnitin login class id and password
If you are a student, seeing the phrase "Turnitin login class ID and password" on your syllabus for the first time can be a bit confusing. Unlike most websites where you just create an account and you're done, Turnitin requires specific credentials from your instructor to ensure your work ends up in the right digital classroom. Class IDs usually expire after the semester ends
This report clarifies what these credentials actually are, how they work, and—most importantly—what you should do when searching for them. how they work