Insert radio button inside payment_fields function

问题:

I an developing a custom payment method for WooCommerce. I want to add three radio buttons after my payment method is selected, just like the below screenshot. I have added the radio buttons successfully with this function.

<?php
/*
Plugin Name: Custom Payment Gateway
Description: Custom payment gateway example

*/

if ( ! defined( 'ABSPATH' ) ) {
    exit; // Exit if accessed directly
}

/**
 * Custom Payment Gateway.
 *
 * Provides a Custom Payment Gateway, mainly for testing purposes.
 */
add_action('plugins_loaded', 'init_custom_gateway_class');
function init_custom_gateway_class(){

    class WC_Gateway_Custom extends WC_Payment_Gateway {

        public $domain;

        /**
         * Constructor for the gateway.
         */
        public function __construct() {

            $this->domain = 'custom_payment';

            $this->id                 = 'custom';
            $this->icon               = apply_filters('woocommerce_custom_gateway_icon', '');
            $this->has_fields         = false;
            $this->method_title       = __( 'Custom', $this->domain );
            $this->method_description = __( 'Allows payments with custom gateway.', $this->domain );

            // Load the settings.
            $this->init_form_fields();
            $this->init_settings();

            // Define user set variables
            $this->title        = $this->get_option( 'title' );
            $this->description  = $this->get_option( 'description' );
            $this->instructions = $this->get_option( 'instructions', $this->description );
            $this->order_status = $this->get_option( 'order_status', 'completed' );

            // Actions
            add_action( 'woocommerce_update_options_payment_gateways_' . $this->id, array( $this, 'process_admin_options' ) );
            add_action( 'woocommerce_thankyou_custom', array( $this, 'thankyou_page' ) );

            // Customer Emails
            add_action( 'woocommerce_email_before_order_table', array( $this, 'email_instructions' ), 10, 3 );
        }

        /**
         * Initialise Gateway Settings Form Fields.
         */
        public function init_form_fields() {

            $this->form_fields = array(
                'enabled' => array(
                    'title'   => __( 'Enable/Disable', $this->domain ),
                    'type'    => 'checkbox',
                    'label'   => __( 'Enable Custom Payment', $this->domain ),
                    'default' => 'yes'
                ),
                'title' => array(
                    'title'       => __( 'Title', $this->domain ),
                    'type'        => 'text',
                    'description' => __( 'This controls the title which the user sees during checkout.', $this->domain ),
                    'default'     => __( 'Custom Payment', $this->domain ),
                    'desc_tip'    => true,
                ),
                'order_status' => array(
                    'title'       => __( 'Order Status', $this->domain ),
                    'type'        => 'select',
                    'class'       => 'wc-enhanced-select',
                    'description' => __( 'Choose whether status you wish after checkout.', $this->domain ),
                    'default'     => 'wc-completed',
                    'desc_tip'    => true,
                    'options'     => wc_get_order_statuses()
                ),
                'description' => array(
                    'title'       => __( 'Description', $this->domain ),
                    'type'        => 'textarea',
                    'description' => __( 'Payment method description that the customer will see on your checkout.', $this->domain ),
                    'default'     => __('Payment Information', $this->domain),
                    'desc_tip'    => true,
                ),
                'instructions' => array(
                    'title'       => __( 'Instructions', $this->domain ),
                    'type'        => 'textarea',
                    'description' => __( 'Instructions that will be added to the thank you page and emails.', $this->domain ),
                    'default'     => '',
                    'desc_tip'    => true,
                ),
            );
        }

        /**
         * Output for the order received page.
         */
        public function thankyou_page() {
            if ( $this->instructions )
                echo wpautop( wptexturize( $this->instructions ) );
        }

        /**
         * Add content to the WC emails.
         *
         * @access public
         * @param WC_Order $order
         * @param bool $sent_to_admin
         * @param bool $plain_text
         */        

        public function payment_fields(){

            if ( $description = $this->get_description() ) {
                echo wpautop( wptexturize( $description ) );
            }
			echo '<input type="radio" name="gender" value="male"> Male<br>
			<input type="radio" name="gender" value="female"> Female<br>
			<input type="radio" name="gender" value="other"> Other';
         /**
         * Process the payment and return the result.
         *
         * @param int $order_id
         * @return array
         */
		 
		public function generate_form($order_id){
			global $woocommerce;

        // Get this Order's information so that we know
        // who to charge and how much
        $customer_order = new WC_Order($order_id);
		
		$_instructions     = $this->instructions;
        $_order_status    = $this->order_status;
        
		
		$items = $customer_order->get_items();
		$product_name  = array();
		foreach ( $items as $item ) {
			array_push($product_name, $item['name']);
		}
		$_Description   = implode(", ", $product_name);
		echo '<strong>Gender</strong>'.$_POST['gender'] ;
		//here is the part where i want to get the value of form inside payment_fields() fucntion 
		exit;	
		} 
        
}

The point is I want to add a form instead of a credit card form after my payment method is selected, and then get the value of that form.