Hi joshjack,
The transcode api currently only support RTSP streams, RTMP streams, and existing EMS streams. In your case you are using a different kind of stream.
However, you can try using the launchProcess API. https://evostream.com/support/documentation/api-definition-guide/evostream-media-server-api/#launchProcess
Below is just one example of how it is used, but you should take a look at the link above to get familiarized with the parameters to the API you can use in your case.