Configuring VitalPBX SIP For Outbound

Dear community,

I have installed VitalPBX on my VPS (Centos 7) and i am trying since couple of hours to configure my sip trunk for outbound calling but i keep receiving in the status report that my sip is unreachable.

I would like to ask where can i find documentation for proper configuration for outbound dialing and what is the proper SIP Trunk format ? I have bought the SIP from freezvon.ru.

Thank you very much,

for the time dedicated

Kind regards,

D.