I am trying to develop a trigger that has a file as one of the output fields. When I use my app with other apps like uploading a file to google drive or sending an email in outlook with a file attachment, I get this error from testing the action.

Stack trace: Error: Got 400 - <?xml version="1.0" encoding="UTF-8"?> <Error><Code>MalformedPOSTRequest</Code><Message>The body of your POST request is not well-formed multipart/form-data.</Message>

I followed the example code from this repo - https://github.com/zapier/zapier-platform-example-app-files

Additionally, the response from my API on the Monitoring page shows a 200 code. There are not many more details than this so I am unsure what the problem is or how to find it.