Do you have any special characters in your secret access key?
Make sure you encode them properly:
https://winscp.net/eng/docs/session_url#special

Or have WinSCP generate the script/code from your working GUI session:
https://winscp.net/eng/docs/ui_generateurl#script

Non-encoded credentials can be provided using -password switch:
https://winscp.net/eng/docs/scriptcommand_open#password

Hello I hope you can help me, I try to connect to pass a file to my Amazon bucket, through the graphic interface I do it without problem, but when I take out the command and run it through CMD I can't open the connection. I set the log with some attempts to connect cmd and by PowerShell.