Unable to upload transientDocuments via Alteryx

I tried uploading document via ETL (Alteryx) and everytime getting the error as mentioned below:

{"code":"INVALID_MULTIPART","message":"An invalid multipart was specified"}

Please provide a proper format of input request in JSON format using same sample file.

I took the reference from the following website for creating/formnatting the payload.

https://swagger.io/docs/specification/describing-request-body/file-upload/