how to get the _navigatingURL value in xbase++?

Question

I am implementing SSO in a legacy app and I am using XbpHTMLViewer2 to open a modal and navigate to my login page in order to intercept the navigation request.

First I open the modal and redirect to my localhost login page http://localhost:5000/core/Index.html

after entering my credentials I logged in correctly and also it gets the accessTokenId value but I can't get the accessTokenId and save it in a new variable

"http://locahost:5000/core/Indext.html?accessTokenId=0aafe0d8-5323-4414-ba2f-ea058be15883"

when I debug the app using xbase IDE there is a _navigatingURL property that contains the value I need but I can't access it.

any workaround or suggestion, I will really appreciate

  #include "xbp.ch"

  PROCEDURE Main()
   LOCAL oDlg
   LOCAL oXbp
   LOCAL oXbp1

     SET CHARSET TO ANSI

     // Create a form for hosting the HTML viewer object
     oDlg := XbpDialog():new( AppDesktop() )
     oDlg:taskList := .T.
     oDlg:create( ,,, {640,480} )
     CenterControl( oDlg )

     // Create the HTML viewer object and arrange for it to cover the form's
     // content area
     oXbp := XbpHTMLViewer2():new( oDlg:drawingArea )
     oXbp:layoutAlign := XBPLAYOUT_LEFT + XBPLAYOUT_TOP + XBPLAYOUT_RIGHT + XBPLAYOUT_BOTTOM
     oXbp:create( ,, {10,10}, {600,420} )

     oXbp:navigate( "http://localhost:5000/core/Index.html" )

     oDlg:showModal()

     oXbp1 := oXbp // BREAKPOINT   <---------------**strong text**

     oDlg:destroy()
  RETURN


  PROCEDURE AppSys()
     // Prevent creation of the default console window
  RETURN