Add Extra field in Billing Address Form on checkout page in Woocommerce

Below code should be added in theme's functions.php file to add an extra Filed in Billing Address Form on checkout page , below code sample is to add 'Land-line Phone' Filed .

// Hook in*/
add_filter( 'woocommerce_checkout_fields' , 'custom_override_checkout_fields' );
 
// Our hooked in function - $fields is passed via the filter!
function custom_override_checkout_fields( $fields ) {
     $fields['billing']['shipping_Landlinephone'] = array(
        'label'     => __('Landline Phone', 'woocommerce'),
    'placeholder'   => _x('Landline Phone', 'placeholder', 'woocommerce'),
    'required'  => false,
    'class'     => array('form-row-wide'),
    'clear'     => true
     );
 
     return $fields;
}

function display_shipping_Landlinephone($order){
    echo "<p><strong>Landline Phone:</strong> " . $order->order_custom_fields['_shipping_Landlinephone'][0] . "</p>";
}

add_action( 'woocommerce_admin_order_data_after_billing_address', 'display_shipping_Landlinephone', 10, 1 );


//validate Field */
add_action('woocommerce_checkout_process', 'billing_phone_checkout_field_process');
 
function billing_phone_checkout_field_process() {
    global $woocommerce;
 
    // Check if set, if its not set add an error.
    if (!$_POST['billing_phone'])
         $woocommerce->add_error( __('Please enter something into Land-line Phone field.') );
}