Send a message to a specific user or session. More information: https://docs.microsoft.com/windows-server/administration/windows-commands/msg.
msg {{username|session_name|session_id}} {{message}}
echo "{{message}}" | msg {{username|session_name|session_id}}
msg /server:{{server_name}} {{username|session_name|session_id}}
msg *
msg /time:{{seconds}}