Custom button widget issue

My customized button widget isn't functioning correctly in preview, test, or run modes. When you click on a certain place, it works. To go to the page, I have added a custom action to the button widget.
import '/backend/backend.dart';
import '/backend/supabase/supabase.dart';
import '/flutter_flow/flutter_flow_theme.dart';
import '/flutter_flow/flutter_flow_util.dart';
import '/custom_code/widgets/index.dart'; // Imports other custom widgets
import '/custom_code/actions/index.dart'; // Imports custom actions
import '/flutter_flow/custom_functions.dart'; // Imports custom functions
import 'package:flutter/material.dart';
// Begin custom widget code
// DO NOT REMOVE OR MODIFY THE CODE ABOVE!

import 'package:flutter_cashfree_pg_sdk/api/cfpaymentgateway/cfpaymentgatewayservice.dart';

void main() {
  runApp(const PayButton());
}

class PayButton extends StatefulWidget {
  final double? height;
  final double? width;

  const PayButton({super.key, this.height, this.width});

  @override
  State<PayButton> createState() => _PayButtonState();
}

class _PayButtonState extends State<PayButton> {
  @override
  void initState() {
    super.initState();
    CFPaymentGatewayService();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              // SizedBox ensures that ElevatedButton expands to full width.
              SizedBox(
                width: double.infinity,
                height: 40,
                child: ElevatedButton(
                  style: ElevatedButton.styleFrom(
                    foregroundColor: const Color.fromARGB(255, 241, 244, 248),
                    backgroundColor: const Color.fromARGB(255, 78, 180, 217),
                    shape: RoundedRectangleBorder(
                      borderRadius: BorderRadius.circular(8),
                    ),
                  ),
                  onPressed: () {
                    // Entire button area will be clickable.
                    print("Proceed to Pay pressed");
                  },
                  child: const Text(
                    'Proceed to Pay',
                    style: TextStyle(fontSize: 16, fontWeight: FontWeight.w500),
                  ),
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}