What do you mean with upload-folder?
If you mean the folder to upload the file to, then I have honestly no idea. Where is it defined in your example? Guess it would either be in the path, query- or body-parameter.
If you mean the source of the file to upload then is it in my example the first HTTP Request node that downloads the file. You can replace that with whatever you want to either read from the local hard drive (Read Binary File) or get it from another service (Dropbox, NextCloud, FTP, …).