invalid constant value in flutter

How to fix this Constant value error

                  actions: [
                IconButton(
                   
                      icon: Icon(
                        Icons.cancel,
                        color: Colors.red,
                      ), onPressed: () { 
                        Navigator.pop(context);
                       },
                    )

              ]

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I have provided a code snippet for a Flutter application that includes an IconButton widget with an icon for the cancel button. When the button is pressed, the current screen is displayed using Navigator.pop(context) How to implement pop from navigation layer ?