Example:
curl -u admin:password -k -L -f https://localhost:5434/c/company/faktura-vydana/1.pdf -o file.pdf
-u specifies the authorization credentials for Flexi.
-L follows redirects. If the URL structure changes in the future, this flag ensures the script will continue to work.
-o ensures that the returned data will be written to the file "file.pdf".
-f specifies that if a server-side error occurs, nothing should be written to the output — the command should exit immediately instead.
-k if you are using a self-hosted installation with an auto-generated certificate, you need to ignore the untrusted certificate authority.
-T the file being sent (request body)
cURL has its own documentation.