What you are referring is a dial plan issue.
When you dial a number, Voxalot matches it with the dial plan you have setted, adding three more rules:
1. If not resolved by your setted rules, it test the number against ENUM roots (number shouldn't be preceded by '00', starting with e164 country code, for examples, 1 xxx xxx xxxx);
2. If the number starts with a star, it tries the number with SIP Broker;
3. If the number starts with 883 5100 x. routes it through Voxbone iNum.
So, you should, first of all:
1. Configure your VSP for call out (Voxalot is a PBX, not a VoIP termination service);
2. Configure your dial plan to route your call through the configured VSP.
You can see some tutorial at
Main Page - Voxalot FAQ.
Regards,