If you give your Unlock Code to someone else, that person can add one test to their Student Dashboard.
This means that you can transfer the Unlock Code to anyone just by letting that person know the code. Instructions on how to use an Unlock Code are here.
However, if a teacher or school gave you the Unlock Code, the test will be attached to that teacher or school. This means that the teacher or school will be able to grade and review the test results.