You seem to have quotes wrong.
It should be like:

See https://winscp.net/eng/docs/commandline#syntax

The easiest is to have WinSCP GUI generate a script template for you:
https://winscp.net/eng/docs/ui_generateurl#script

Hey,

I am trying to export some files on my local folder to an SFTP location using SSIS....I need the command line to accept the hostkey always. Can you please let me know what am i missing here?

/command "open sftp://myusername:mypassword@myportal -hostkey="ssh-rsa 2048 ...........................="" "put D:\xxx\xxx\*.CSV /xxx/xxxx/" "exit"