Selected 1

import 'package:flutter/material.dart';
import 'package:gap/gap.dart';

String selectedGender = 'Male';
final listGender = ['Male', 'Female'];

Column(
  crossAxisAlignment: CrossAxisAlignment.start,
  children: [
    const Text(
      'Gender:',
      style: TextStyle(
        fontWeight: FontWeight.bold,
        fontSize: 14,
      ),
    ),
    const Gap(10),
    ...listGender.map((e) {
      return Row(
        children: [
          Radio(
            value: e,
            groupValue: selectedGender,
            onChanged: (value) {
              if (value == null) return;
              selectedGender = value;
              setState(() {});
            },
            visualDensity: const VisualDensity(
              horizontal: VisualDensity.minimumDensity,
              vertical: VisualDensity.minimumDensity,
            ),
          ),
          const Gap(10),
          GestureDetector(
            onTap: () {
              selectedGender = e;
              setState(() {});
            },
            child: Text(
              e,
              style: const TextStyle(
                fontWeight: FontWeight.w400,
                fontSize: 14,
              ),
            ),
          ),
        ],
      );
    }),
  ],
),