When you have finished all the courses in a Level, you can claim your certificate for that level.
To do this, click on the tab for the relevant certificate and then on the image (rather like taking a course).
It is recommended that you claim your Level I and Level II certificates as you work through the Program. However, to access the courses in any level (II or III) it is necessary only to have completed the courses in the prior levels (I and II, respectively). In other words, you could choose to work through to the end of Level III, and claim only the Level III certificate.