I am working on C# platform and exploring it. I am trying to use Fax api and trying to download the fax attachment content in the code. I can see I get the binary data as output as response of the API once I input the message and attachment id:
https://platform.devtest.ringcentral.com/restapi/v1.0/account/accountId/extension/extensionId/message-store/messageId/content/attachmentId