How do I add/remove non-device contacts on my whitelist?

If you want to whitelist contacts that aren’t stored in your device contacts, you can manually add them to your whitelist. 

Go to the Whitelist page and you’ll see your whitelisted contacts sorted into On your phone and Others. Underneath Others, tap Add to whitelist, then fill out the contact’s information and Add it.

You’ll see the contact added to your whitelist under Others, which shows all manually whitelisted contacts. You can remove these contacts from the whitelist at anytime by swiping left on the contact and pressing Delete.