[Q] Voip + Server error topic

So I have an obi200 and have bought a key from freephoneline.

I have followed the settings and everything step-by-step from FPL's support page that shows the required settings

and to no avail I still get 'Server error. Please try again' whenever I try calling, it'll ring twice only. The settings has been approved in the call settings, if not, it'll say 'still trying'.