1. Go to User groups (Managers) -> Users and add a new one:

2. Press "+" near Technologies -> SIP:

Press Generate button on the right of secret row.
Save.
3. Go to Users (ann) -> Extensions and add "100":

1. Go to User groups (Managers) -> Users and add the new one:

2. Press "+" near Technologies -> SIP:

Press Generate button on the right of secret row.
Save.
3. Go to Users (john) -> Extensions and add "101":
