How to reduce volume of all events while playing any vocal?

I have too many sound/music events.
But when a vocal is playing , all of other playing events volume must reduced to 70% or less. How can i do that?!

I have 3 VCA in my project.
Music VCA
Effect VCA
Vocal VCA

In other words, i want when an event that assigned to Vocal VCA is playing, other VCA volumes reduce to 70%.

Is it any prebuild facilities for doing that in FMOD Studio? or maybe i need to handle it by API programing.

Thank you for any help

You might want to automate your vca volume with a sidechain.
See this video for more on sidechains