I am building a system to add tickets through the API.

There is the option for uploads as a list in the create ticket API call; however I seem to be unable to include a file when creating a ticket. I get UNSUPPORTED MEDIA TYPE if the content-type header is application/json - and I get no response (and no ticket) if the content-type is multipart/form-data and the closest I can find to support is this 2 year old ticket using I think a different version of the API: Here

Perhaps I'm doing this wrong- but is the only way to include a file on a newly created ticket with APIs to upload the file first through it's own API call and include the id of the upload as that list for uploads in the new API ticket? Or do I have to create ticket, create the upload, then relate the upload ID to the ticket ID with the assign upload API route for 3 separate API calls?

Thanks in advance