Access APM parameter from `ParameterEditorController.cc`

Hi all, I am trying to access the parameter from flightDisplayViewMap.qml but I got the value of 0 from WPNAV_SPEED .

Although, I can access the value of WPNAV_SPEED of 500 in ParameterEditor.qml. I am scratching my head over this. Any help would be appreciated.

I solve my problem thanks.