Use onTap() or onPressed() with FlutterIcons on a Bottom Navigation Bar

I have a Bottom Navigation Bar using FlutterIcons and I would like to use either onTap() or onPressed() on them to switch between screens in the app. How can I achieve this?

Here's my code snippet:

      bottomNavigationBar: CurvedNavigationBar(
        backgroundColor: Constants.scaffoldBackgroundColor,
        buttonBackgroundColor: Constants.primaryColor,
        items: [
            Icon(
            FlutterIcons.ios_home_ion,
            size: 20.0,
            color: activeIndex == 0 ? Colors.white : Color(0xFF000B70),
          ),
          Icon(
            FlutterIcons.file_pdf_box_mco,
            size: 20.0,
            color: activeIndex == 1 ? Colors.white : Color(0xFF000B70),
          ),
          Icon(
            FlutterIcons.qrcode_scan_mco,
            size: 20.0,
            color: activeIndex == 2 ? Colors.white : Color(0xFF000B70),
          ),
          Icon(
            FlutterIcons.notifications_active_mdi, 
            size: 20.0,
            color: activeIndex == 3 ? Colors.white : Color(0xFF000B70),
          ),
          Icon(
            FlutterIcons.setting_ant,
            size: 20.0,
            color: activeIndex == 4 ? Colors.white : Color(0xFF000B70),
            
          ),
                  
       ],

        onTap: (index) {
          setState(() {
            activeIndex = index;
          });
        },
      ),

CurvedNavigationBar doesn't provide onPressed, use onTap as you've define.

bottomNavigationBar: CurvedNavigationBar(
  items: [
  ],
  
  onTap: (index) {
    setState(() {
      activeIndex = index;
    });
  },
  body:yourWidgetList[activeIndex]
),

More about curved_navigation_bar

Demo widget

class AGG extends StatefulWidget {
  const AGG({Key? key}) : super(key: key);

  @override
  State<AGG> createState() => _AGGState();
}

class _AGGState extends State<AGG> {
  List<Widget> pages = [
    Text("Page 1"),
    Text("Page 2"),
    Text("Page 3"),
  ];

  int activeIndex = 0;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      bottomNavigationBar: CurvedNavigationBar(
        backgroundColor: Colors.blueAccent,
        items: <Widget>[
          Icon(Icons.add, size: 30),
          Icon(Icons.list, size: 30),
          Icon(Icons.compare_arrows, size: 30),
        ],
        onTap: (index) {
          setState(() {
            activeIndex = index;
          });
        },
      ),
      body: pages.elementAt(activeIndex),
    );
  }
}

You can explore more about BottomNavigationBar