How to Hide the "Pricing Table" Admin Menu

function plt_hide_b_pricing_table_menus() {
	//Hide the "Tools → Pricing Table" menu.
	remove_submenu_page('tools.php', 'b-pricing-table');
}

add_action('admin_menu', 'plt_hide_b_pricing_table_menus', 11);

Where do I put this code?