1- Settings->Accounts-> SIP

2-
Account Name: choose any name
Display as : write 00 and your number(e.g. 0015672580000).
Username: your number (e.g. 15672580000).
Password: Your number password.
Domain: sip.businessnumbers.net
Click Save.

3-
Click Enabled.

4-

5-
Your number now is online ( registered).
and you can receive or send calls.
