Hello ,
I'm using ringcentral-web-phone/index.js at master · ringcentral/ringcentral-web-phone (github.com) this code that is working fine with sandbox credentials. It means that when I try to call outside to any US number, the call gets connected, but when using production credentials to try to call any US number, I'm not able to make the call, even though the number that I'm using has the digital line to it.
It's worth noting that when I use the production credentials to call the number in the user's extension (service account -> users -> Users with Extensions), the call is connected to that number.