[Solved] Plug-in not showing sidechain button (in Cubase)

I’m working on adding sidechain support to a VST3 effect plug-in, but when I run in Cubase, the little sidechain button at the top does not show up. I have added the extra input in setBusArrangements() with this call:

addAudioInput(USTRING(“Aux In”), Steinberg::Vst::SpeakerArr::kMono, kAux, 0 );

Is there something else I need to do (besides handling the processing itself, of course)?

I’ve compared against AGainWithSideChain, and don’t see anything I’m missing. Anyone know what makes Cubase show the sidechain button?

Never mind. I had to add that code in the initialize() function also. I guess it’s too late at the time of setBusArrangements() for Cubase to know to enable the side-chain for my plug-in.