Try the following steps:
- Open the whisper list feature
- Create a new list (hotkey is needed but does not matter)
- Add your target or targets to the list (you may use a server group)
- Now go into the hotkey list
- Change the hotkey to “On key down → Whisper → Activate Whisperlist”
- Create a second and different hotkey “On key down → Whisper → Dectivate Whisperlist”
After:
- Press Hotkey one to whisper
- Press Hotkey two to stop whispering
These are examples, not every step has to be done as I wrote. As well make sure, you have enough permission to whisper to your targets.