I have the instructions from the knowledge base:
https://support.ringcentral.com/article/Set-Caller-ID-Outgoing-Fax-RingCentral-Online-Account.html
But the fax line for the site I am trying to configure is not an available option. How do I make it appear in the list?
Are you the admin on the account?
Have you checked if the number is a Fax Number?
Go to Phone System > Phone Numbers > All Numbers.
Take note that numbers assigned to other extensions can't be used as your Outbound Fax Caller ID.
It is assigned to the fax line's extension. Can I not make other user's outbound caller ID show as the main inbound number?
Enter your E-mail address. We'll send you an e-mail with instructions to reset your password.
