Connecting to external gear - Avid HDX


I am trying to figure out how to connect external gear to Wavelab 8.5.10. I successfully configured audio to be routed through my HD IO convertors, but I have a problem to connect e.g. my Manley Vari Mu and Dangerous BAX EQ.
This is the VST Audio connections screen, where I defined the IO for the Manley (on the Avid HD IO):
ASIO Plugins.png
When I select in the master section the External Gear, nothing happens:
external gear.png
Is it possible to have multiple external gear plugins inline, or do they need to be patch externally?

I am a newbie in WL, so any help on this is appreciated.
Thanks for your help!

You can have a single external gear plugin. But your external devices can be serialized together, of course.