TIdSMTP - Identifier not found

I tried to use the Indy lib in my WEBCore app, but compile fails due to "Identifier not found".
The Delphi paths are ok, so I assume I have add some paths for WebCore?
Having tried to add the paths to WebCore Options/Library path ends with "unit Windows not found". So I thing I am missing something here.

Can you pls help me out? Thank you!

Indy components are not TMS WEB Core components and can as such, not be used.
Windows unit is also Windows specific and cannot be used for browser based applications that TMS WEB Core generates.