Only providers can whitelist clients, and TER doesn't know you are a provider until you link your username to your reviews. If you have reviews, contact admin and have them link them. If you don't have any, then you have to wait until you get your first review, then you can ask admin to link them to your username. This will provide you with "limited provider VIP' giving you access to the PM system and your own reviews and should also allow you to whitelist. It will aslo provide a link to your reviews every time you post. Below is a lnk to the whitelist FAQ.
Also check out the self help manual if you haven't already.
good Luck