"Upload file to signed URL" action not sending the binary file

Hi,

I’m trying to upload a file directly to Amazon S3 with a signed URL (obtained via the backend).

What I have done:

  • Create element ‘File upload’
  • Add workflow with action ‘Upload file to signed URL’ → here I inserted:
    • File to upload: “File upload - value” (selected from the File upload element)
    • Signed Upoad URL: the url obtained via the backend.

Now my problem is that this workflow results in NOT sending the actual file as the body, BUT instead it sends the file metadata like this:

{
"id": "...",
"mimeType": "image/png"
}

My question: What am I doing wrong here? Why is the actual file not being sent? How do I fix this?