Using mutes with brass

So I’m currently working on a piece where I’d like the trumpets to switch to harmon mutes. I’ve gotten far enough to setup the expression maps, but I can’t get the keyswitch setup right. I don’t see which keys are used for the different techniques. I’m using the HALion SE that comes with dorico btw.

Thanks for the help

Which sound are you using? I don’t know which trumpet sounds included with Dorico include a variety of mutes.