Can't access my lonestar6 TACC terminal through WinSCP

I can't seem to log into my terminal to run a slurm script in WinSCP. Kindly advise me. Error says "Server refused to start a shell/command". Could this be a WinSCP issue?

What protocol are you trying? SFTP? Can you login to your server using any other SFTP client?
Note that WinSCP is not commonly used to "run scripts". It's not (shell) terminal, it's file transfer application.