I tried with POSTMAN to upload a file to my endpoint host/jsonapi/file/file, the POST method is available but when I try to upload something, drupal gives me a 415 unsupported media type error. I tried with the binary option and with the data-form option using the next headers:
"Accept: application/vnd.api+json" "Content-Type: application/octet-stream" 'Content-Disposition: file; filename="test.jpg"'
The GET method works well. It returns me all the files.
What is wrong?