Add New Block style to the heading in Gutenberg WP Editor

<?php
/**
 * Add new h4 block style.
 * Add custom styles and scripts support for the Block Theme.
 *
 * @package Safari_Block_Theme
 */

if ( function_exists( 'register_block_style' ) ) {
	register_block_style(
		'core/heading',
		array(
			'name'         => 'question', // WP will generate a style named - "is-style-question".
			'label'        => 'Question Style',
			'inline_style' => 'question',
		)
	);
}

/**
 * Add custom styles and scripts support for the Block Theme.
 *
 * @return void
 */
function safaris_enqueue_scripts() {

	$blockPath = '/css/blocks/h4.css';

	wp_enqueue_style(
		'safaris-blocks-theme',
		get_template_directory_uri() . $blockPath,
		'',
		filemtime(get_template_directory() . $blockPath),
		'all'
	);
}

// Adds the style to block editor backend only.
// add_action('enqueue_block_editor_assets', 'safaris_enqueue_scripts');

// Adds the style to both the front and backend editor.
add_action('enqueue_block_assets', 'safaris_enqueue_scripts');