Universities reset their class IDs every semester. A Class ID from Fall 2021 is almost certainly deleted or archived by the start of 2024/2025. These keys are expired digital ghosts. Even if you type them in, the Turnitin server will return an error: "Invalid Class ID or Enrollment Key."
If your instructor provides you with a Class ID and Enrollment Key, use them as follows: free turnitin class id and enrollment key 2021
: Many schools offer free access through their writing labs even if you aren't currently enrolled in a specific class that uses it. Universities reset their class IDs every semester