How to record midi keyboard vst instrument in obs?

[new-to-obs]

Hi,
I want to record (not live stream) from various sources
1. audio from a mic
2. images from several window captures
3. music generated from a midi keyboard. I have a virtual instrument installed (Ohio piano vst), and I want that sound to be recorded.

Is there a way to do it?
Thanks

 

[new-to-obs]

I see adding source "audio output capture" does the trick.