I did not have any problems setting it up for voipcheap. Here is a setup instructions, you just plug in appropriate settings as needed. Below that is another one from the Nokia support forums.
Nokia E63 SIP Settings VoIP Setup SIP Client Configuration
http://discussions.nokia.com/t5/Eser...gs/td-p/525829
Phones: Xiaomi Mi Mix 2, Samsung Galaxy A50, ASUS zenfone 3,
Sim cards: AT&T (Contract), 3 UK, Piranha Mobile