External Teams Call - Unavailable Error

[Viityaa]

I have an external call license, however when trying to make calls it rings once then comes up with the below message.

I have tested multiple landlines and mobiles; both bring up this message.

Does anyone know why this would appear when I have the required license?

[#2]

@Viityaa What do you mean by an "external call license"? Are you referring to Phone System or a Calling Plan? If you don't have a Calling Plan, are you using Direct Routing or Operator Connect?

[#3]

I mean that my company has provided me with the appropriate license to be able to call externally through Teams.
I have also found this note if that helps?

Client error 484 Address incomplete.

[#4]

You will need to work with your company's IT department to get this resolved.