V18: On the SIP Trunk, DIDs page, you need to add the DID. Then on inbound rules point it or don't add it in inbound rules and the Add DID button you are using will work.I add a sip trunk to PBX ( with voip.ms) and went to setup the Fax server, under Direct Inbound Dialing (DID) tried Adding a DID getting error:
No DID/DDIs to assign
could not find resources how to set it up
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