curl mit @ im Dateinamen nach Pascal übersetzen

[Kas Ob.]

I am afraid that there is no easy way (ready to be used API), and these files should be manually formed into a body request.

This show the structure
https://microsoft.public.winhttp.nar...part-form-data

The most important is the Content-Disposition to be filled right, and you must fill the "Content-Type: multipart/form-data; boundary=" not leaving it to be filled automatically.

Also you don't need that much of '-', in "boundary=" it is shorter by '-', in fact you don't need them at all in in the HTTP header, only in the body as separator you need 2 dashes "--".