Gutenberg. How To Register A Custom Block Style For Specific Post Type Only

How can I make this working?

Not sure if there’s a better way, but I’d use subscribe() in the @wordpress/data package:

const { registerBlockStyle } = wp.blocks;
const { subscribe, select } = wp.data;

wp.domReady( () => {
    const unsubscribe = subscribe( () => {
        const postType = select( 'core/editor' ).getCurrentPostType();

        // 1. Unsubscribe once we've got the post type.
        if ( postType ) {
            unsubscribe();
            console.log( `Post type: ${ postType }. Unsubscribed.` );

            // 2. Register the block style if the post type is 'post'.
            if ( 'post' === postType ) {
                registerBlockStyle( 'core/paragraph', {
                        name: 'lead',
                        label: 'Lead'
                } );
            }
        }
    } );
} );