I can simply create a new Conversation using the default Conversation Service using Twilio.Rest.Conversations.V1.Create() but how do I create a new Conversation using a particular (non-default) Conversation Service using the API? I can fetch the Conversation service I want: ServiceResource.Fetch(pathSid: "ISxxxxxxxxxxxxxxxxx") but I can't see how to use that to create a new Conversation.
Is it not supported through programmatic API, and do I need to use the raw json to the URL instead?