WindowManager: BadTokenException with Accessibility service context

Question

class MyServiceClass : AccessibilityService() {
  
  private val overlayParams = WindowManager.LayoutParams(
        WindowManager.LayoutParams.MATCH_PARENT, WindowManager.LayoutParams.MATCH_PARENT,
        WindowManager.LayoutParams.TYPE_ACCESSIBILITY_OVERLAY, overlayFlags,
        PixelFormat.TRANSLUCENT
    ).apply {
        gravity = Gravity.TOP
    }

  override fun onServiceConnected() {
     val windowManager = baseContext.getSystemService(WINDOW_SERVICE) as WindowManager
     val overlayLayout = FrameLayout(context)
     windowManager.addView(overlayLayout, overlayParams)//here I have the exception
  }

}

I have a service class which extends AccessibilityService.

There, onServiceConnected callback, I try to add a view to window manager and I have the following exception:

android.view.WindowManager$BadTokenException: Unable to add window -- token null is not valid; is your activity running?

What could be the reason? Is it that I am adding too early, or could the service got killed while triggering onServiceConnected?