How to Hide Ads by datafeedr.com Admin Menus

function plt_hide_ads_by_datafeedrcom_menus() {
	//Hide "Settings → Ads".
	remove_submenu_page('options-general.php', 'dfads-settings');

	//Hide "Ads".
	remove_menu_page('edit.php?post_type=dfads');
	//Hide "Ads → All Ads".
	remove_submenu_page('edit.php?post_type=dfads', 'edit.php?post_type=dfads');
	//Hide "Ads → Add New Ad".
	remove_submenu_page('edit.php?post_type=dfads', 'post-new.php?post_type=dfads');
	//Hide "Ads → Groups".
	remove_submenu_page('edit.php?post_type=dfads', 'edit-tags.php?taxonomy=dfads_group&post_type=dfads');
}

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

Where do I put this code?