How to add a heading in between checkout fields of WooCommerce

add_action( 'woocommerce_form_field_text','reigel_custom_heading', 10, 2 );
function reigel_custom_heading( $field, $key ){
    // will only execute if the field is billing_company and we are on the checkout page...
    if ( is_checkout() && ( $key == 'billing_company') ) {
        $field .= '<p class="form-row form-row-wide">Custom Heading</p>';
    }
    return $field;
}

// Add field type to WooCommerce form field 
add_filter( 'woocommerce_form_field_heading','sc_woocommerce_form_field_heading', 10, 4 );
function sc_woocommerce_form_field_heading($field, $key, $args, $value) {
    $output = '<h3 class="form-row form-row-wide">'.__( $args['label'], 'woocommerce' ).'</h3>';
    echo $output;
}

// Modify checkout fields
add_filter( 'woocommerce_checkout_fields','custom_override_checkout_fields' );
function custom_override_checkout_fields( $fields ) {
    $fields['billing']['billing_heading_name'] = array(
        'type'      => 'heading',
        'label'     => 'Heading here',
    );

add_filter('woocommerce_checkout_fields', 'ac_checkout_reorder_fields');
function ac_checkout_reorder_fields($fields) {
    $fields['billing']['billing_heading_name'] = array(
        'type'      => 'heading',
        'label'     => 'Heading here',
    );
    $order = array(
        "billing_first_name", 
        "billing_last_name", 
        "billing_heading_name",
        "billing_company", 
        "billing_email", 
        "billing_phone",
        "billing_address_1", 
        "billing_address_2", 
        "billing_postcode", 
        "billing_country" 
    );
    foreach($order as $field) {
        $ordered_fields[$field] = $fields["billing"][$field];
    }
    $fields["billing"] = $ordered_fields;
    return $fields;
}

add_filter('woocommerce_form_field', 'addHeadingsInBetweenFormFields', 10, 4);

function addHeadingsInBetweenFormFields($field, $key, $args, $value = null) {

  if (is_checkout() & $key === 'billing_first_name') {
    $a = '<p class="form-row form-row-wide">Shipping</p>';
    return $a . $field;
  }
  return $field;

}