How to implement spacing.blockGap support in custom block?

I have custom block with spacing.blockGap : true in block.json (I just copied it from group block)

"supports": {
	"spacing": {
		"margin": true,
		"padding": true,
		"blockGap": true,
		"__experimentalDefaultControls": {
			"padding": true,
			"blockGap": true
		}
	}
},

This block is just a wrapper with some css grid styles.

// save.js
export default function save(props) {
	const innerBlocksProps = useInnerBlocksProps.save(useBlockProps.save());
	
	return (<div {...innerBlocksProps}></div>)
}

// edit.js
export default function Edit() {
	const innerBlocksProps = useInnerBlocksProps(
		useBlockProps(),
		{
			allowedBlocks: ['my-theme/inner-block'],
		});

	return (<div {...innerBlocksProps}></div>)
}

How do I implement gap support?

The editor displays control for editing.

And When I save I get correct value in attributes:

<!-- wp:my-theme/outer-block {"style":{"spacing":{"blockGap":"var:preset|spacing|60"}}} -->
<div class="wp-block-my-theme-outer-block">
    <!-- wp:my-theme/inner-block --> ... <!-- /wp:my-theme/inner-block -->
</div>
<!-- /wp:my-theme/outer-block-->

But in front-end gap doesn’t applyed to this block.

At the same time if I create build-in group block and set blockGap in front end WP adds new class wp-container-6 with gap styles.

What should I do to tell WP add gap-classes to my block?