Without knowing the exact nature of the problem, I would suggest we first cross-check all the configurations and credentials that you have inputted. Make sure to update everything needed for making a call. Check if the network connectivity is stable and there’s no issue from the server-side. Also, ensure that the number you’re dialing to is active and reachable. If the problem persists, it would be best to reach out for technical support, they could help identify if it’s a software or hardware issue.