If you want your custom button on a product page, you can simply do this by calling the
link_click() function, as Hello Retail already have the meta-data for this specific product. This will trigger the wish list panel to slide out and add the product to the wish list.
// Custom event to trigger the wish list panel to slide out, and add the current product to the wishlist.ADDWISH_PARTNER_NS.link_click();
If you want to show the wish list without adding the current product, you can use
// Custom event to trigger the wish list panel to slide out, without adding a product.ADDWISH_PARTNER_NS.show_panel(true);