WordPress Filter to add default margin and padding controls to the core Heading block

gistfile1.txt

<?php

/**
 * Adds default margin and padding controls to the core Heading block.
 *
 * This filters the block registration arguments for `core/heading` and
 * enables the `__experimentalDefaultControls` settings for spacing,
 * specifically turning on default margin and padding controls.
 *
 * @param array  $args       The block type registration arguments.
 * @param string $block_type The block type being registered.
 *
 * @return array Modified block registration arguments.
 */

function my_theme_heading_default_controls( $args, $block_type ) {
    if ( $block_type === 'core/heading' ) {
        $args['supports']['spacing']['__experimentalDefaultControls'] = [
            'margin'  => true,
            'padding' => true,
        ];
    }
    return $args;
}

add_filter( 'register_block_type_args', 'my_theme_heading_default_controls', 10, 2 );