how to put the check trigger for file transfer success result

Please suggest - how I can add a trigger (criteria) for successful/unsuccessful result of SFTP file transfer made by command mput?
The goal is to stop script if file was not transferred by mput command.
Or proceed next steps in case of successful file transfer

I'm not sure I understand your post.
WinSCP script aborts on any error by default.
See also https://winscp.net/eng/docs/scripting#using_scripting