Quad Cortex as Effekt Unit via Send/Return with the Engl Artist

Hello, I would like to use the Quad Cortex as an effects unit, simply via the send/return of my Engl Artist.
No 4 cable method just loop it in.
What’s the best way to do this, it didn’t work with normal jack cables via the Quad’s send/return sockets?
Thanks for the help
Ralf

Amp send → QC input
QC output 3/4 → Amp return.

The QC send/return connections are for its own effects loops.

Thank you very much, I will try it this way

This doesn’t need to be a feature request as that is used for new features that don’t exist. Thanks!