Thanks for your answer, you made me think of other ways I could make changes.
I applied the changes from the web interface from a local computer in the same network
When I logged in from Obitalk website in the expert mode, I found an exclamation mark:
I didn't change the auto provisioning yet but could you tell me if few words what that setting is useful for please? I looked online but still in doubt.
One more thing, What is the other way to change the default PSTN setting if not from the web interface please?
Thanks!