Create a new shipping method in woocommerce 3

I need help in generating new shipping method in woocommerce version 3+. The name for new field is "Nextday delivery". Like the flat rate it also need to be there in the method but it was not displayed in the drop down select field.

The below is the code which I tried. But it's not working for me.

    function request_a_shipping_quote_init() {
        if ( ! class_exists( 'WC_Request_Shipping_Quote_Method' ) ) {
            class WC_Request_Shipping_Quote_Method extends WC_Shipping_Method {

                public function __construct() {
                    $this->id                 = 'request_a_shipping_quote'; // Id for your shipping method. Should be uunique.
                    $this->method_title       = __( 'Request a Shipping Quote' );  // Title shown in admin
                    $this->method_description = __( 'Shipping method to be used where the exact shipping amount needs to be quoted' ); // Description shown in admin

                    $this->title = "Request a Shipping Quote"; // This can be added as an setting but for this example its forced.

                    $this->supports = array(
                        'shipping-zones'
                    );

                    $this->init();
                }
function init() {
                    $this->init_form_fields(); // This is part of the settings API. Override the method to add your own settings
                    $this->init_settings(); // This is part of the settings API. Loads settings you previously init.


                    add_action( 'woocommerce_update_options_shipping_' . $this->id, array( $this, 'process_admin_options' ) );
                }

                function init_form_fields() {

                    $this->form_fields = array(

                        'enabled' => array(
                            'title'       => __( 'Enable', 'dc_raq' ),
                            'type'        => 'checkbox',
                            'description' => __( 'Enable this shipping method.', 'dc_raq' ),
                            'default'     => 'yes'
                        ),

                        'title' => array(
                            'title'       => __( 'Title', 'dc_raq' ),
                            'type'        => 'text',
                            'description' => __( 'Title to be displayed on site', 'dc_raq' ),
                            'default'     => __( 'Request a Quote', 'dc_raq' )
                        ),

                    );

                }

                public function calculate_shipping( $packages = array() ) {
                    $rate = array(
                        'id'       => $this->id,
                        'label'    => $this->title,
                        'cost'     => '0.00',
                        'calc_tax' => 'per_item'
                    );


                    $this->add_rate( $rate );
                }
            }
        }
    }

    add_action( 'woocommerce_shipping_init', 'request_a_shipping_quote_init' );

    function request_shipping_quote_shipping_method( $methods ) {
        $methods['request_shipping_quote_shipping_method'] = 'WC_Request_Shipping_Quote_Method';

        return $methods;
    }

    add_filter( 'woocommerce_shipping_methods', 'request_shipping_quote_shipping_method' );

I need it to come in the dropdown like flatrate free shipping etc but it was not comming in the dropdown.

There were some missing things and others unnecessary. The correct way to make it work is:

add_action('woocommerce_shipping_init', 'request_shipping_quote_method');
function request_shipping_quote_method() {

    if ( ! class_exists( 'WC_Request_Shipping_Quote_Method' ) ) {
        class WC_Request_Shipping_Quote_Method extends WC_Shipping_Method {

            public function __construct( $instance_id = 0) {
                $this->id = 'request_shipping_quote';
                $this->instance_id = absint( $instance_id );
                $this->domain = 'rasq';
                $this->method_title = __( 'Request a Shipping Quote', $this->domain );
                $this->method_description = __( 'Shipping method to be used where the exact shipping amount needs to be quoted', $this->domain );
                $this->supports = array(
                    'shipping-zones',
                    'instance-settings',
                    'instance-settings-modal',
                );
                $this->init();
            }

            ## Load the settings API
            function init() {
                $this->init_form_fields();
                $this->init_settings();
                $this->enabled = $this->get_option( 'enabled', $this->domain );
                $this->title   = $this->get_option( 'title', $this->domain );
                $this->info    = $this->get_option( 'info', $this->domain );
                add_action('woocommerce_update_options_shipping_' . $this->id, array($this, 'process_admin_options'));
             }

            function init_form_fields() {
                $this->instance_form_fields = array(
                    'title' => array(
                        'type'          => 'text',
                        'title'         => __('Title', $this->domain),
                        'description'   => __( 'Title to be displayed on site.', $this->domain ),
                        'default'       => __( 'Request a Quote ', $this->domain ),
                    ),
                    'cost' => array(
                        'type'          => 'text',
                        'title'         => __('Coast', $this->domain),
                        'description'   => __( 'Enter a cost', $this->domain ),
                        'default'       => '',
                    ),
                );
            }

            public function calculate_shipping( $packages = array() ) {
                $rate = array(
                    'id'       => $this->id,
                    'label'    => $this->title,
                    'cost'     => '0',
                    'calc_tax' => 'per_item'
                );
                $this->add_rate( $rate );
            }
        }
    }
}

add_filter('woocommerce_shipping_methods', 'add_request_shipping_quote');
function add_request_shipping_quote( $methods ) {
    $methods['request_shipping_quote'] = 'WC_Request_Shipping_Quote_Method';
    return $methods;
}

Code goes in function.php file of your active child theme (active theme).

Tested and works.

Here the shipping method selector now displays this "Request a shipping coast" method: