How to Hide EWWW Image Optimizer Admin Menus

function plt_hide_ewww_image_optimizer_menus() {
	//Hide the "Media → Bulk Optimize" menu.
	remove_submenu_page('upload.php', 'ewww-image-optimizer-bulk');
	//Hide the "Tools → EWWW Image Optimizer" menu.
	remove_submenu_page('tools.php', 'ewww-image-optimizer-tools');
	//Hide the "Settings → EWWW Image Optimizer" menu.
	remove_submenu_page('options-general.php', 'ewww-image-optimizer/ewww-image-optimizer.php');
}

add_action('admin_menu', 'plt_hide_ewww_image_optimizer_menus', 61);

Where do I put this code?