connexion reject UPgrade cisco IOS

Hello. My connexion to my Cisco switch is refused. See the screenshot below.

You seem to be trying to use SCP protocol. The SCP protocol implementation in WinSCP works only against Linux (or Linux resembling) servers.
See https://winscp.net/eng/docs/requirements#client
That might not be the case of your Cisco device.

Please try using SFTP.