Action to send NX_KEYTYPE_MUTE (and others)

Without getting into the mostly irrelevant "why", I need to understand the quickest way to assign an action of NX_KEYTYPE_MUTE in BTT, if that's possible.

I use an application that listens for NX_KEYTYPE_MUTE, NX_KEYTYPE_SOUND_UP, and NX_KEYTYPE_DOWN in order to execute some functions, and I need to understand how in BTT to send that to the application.

I have tried just triggering the F10, F11, and F12 keys on my Magic Keyboard, which are supposed to send those messages, but that is not working.

Thanks!

there are dedicated predefined actions for these (mute, volume up, volume down...) they use these keys internally.

Oh goodness I can't believe I missed this. Thank you!!