Send keyboard shortcut to app with multiple windows

I want to send the mute/unmute keyboard shortcut (cmd+shft+m) to Cisco Webex Meetings video calls, regardless of the current app (i.e., global shortcut). I tried mapping, for example, F15 as my shortcut. I have an issue with getting the command to go to the right app. Cisco Webex Meetings has a base app listing upcoming meetings, and then opens what appears to be another app for an individual call.

  1. I can create an app-specific keyboard shortcut by selecting the video call window via "Select app from running apps." Then I can make a simple keyboard shortcut action.
  2. I can create a global trigger and try to "Send shortcut to specific app." However, that app selector doesn't include the video window app where the shortcut can work.

When I look at the .json export, I find this information in #1:

"BTTAppBundleIdentifier" : "com.webex.meetingmanager",
  "BTTAppName" : "Cisco Webex Meetings",
  "BTTAppAutoInvertIcon" : 1,
  "BTTAppProcessMatchMode" : 2,
  "BTTAppProcessName" : "Cisco Webex Meetings",
  "BTTTriggers" : [

And this in #2:

"BTTPredefinedActionName" : "Send Shortcut to Specific App",
      "BTTLayoutIndependentActionChar" : "file:\/\/\/Applications\/Cisco%20Webex%20Meetings.app",
      "BTTAutoAdaptActionToKeyboardLayout" : true,
      "BTTShortcutApp" : "file:\/\/\/Applications\/Cisco%20Webex%20Meetings.app",
      "BTTShortcutSwitchToAppFirst" : "1",
      "BTTShortcutAppUnderCursor" : "com.cisco.webexmeetingsapp",
      "BTTShortcutToSend" : "56,55,46",

Is there a way I can specify a "Send Shortcut to Specific App" to go to the app represented in #1? (E.g., using the current running apps to choose?)

Thanks!

Ever find a solution to this issue? Targeting "Webex Meetings" directly for a global 'mute' shortcut or something similar?