If you're in the UK, try logging into Turnitin at TurnitinUK.com.
If you're anywhere else in the world, you should log in at Turnitin.com.
If you’re in the UK, reset your password here.
If you’re anywhere else in the world, reset your password here.
(For example, Moodle, Blackboard, Canvas etc.)
Turnitin is unable to reset your password as your institution controls these details. Contact the instructor for your class, or any support service your institution provides, and they will be able to help.