Adding Subtitles to WooCommerce Product Post Type

Hi there,

Can you please tell me how and where to Add “Subtitles” to the WooCommerce Product Post Type.

I have looked into your FAQs section on github but I need to know where to insert the below code

function theme_slug_add_subtitles_support() {
    add_post_type_support( 'product', 'subtitles' );
}
add_action( 'init', 'theme_slug_add_subtitles_support' );

https://www.ads-software.com/plugins/subtitles/