How to Hide Snappy List Builder Admin Menus

function plt_hide_snappy_list_builder_menus() {
	//Hide "List Builder".
	remove_menu_page('slb_dashboard_admin_page');
	//Hide "List Builder → Dashboard".
	remove_submenu_page('slb_dashboard_admin_page', 'slb_dashboard_admin_page');
	//Hide "List Builder → Email Lists".
	remove_submenu_page('slb_dashboard_admin_page', 'edit.php?post_type=slb_list');
	//Hide "List Builder → Subscribers".
	remove_submenu_page('slb_dashboard_admin_page', 'edit.php?post_type=slb_subscriber');
	//Hide "List Builder → Import Subscribers".
	remove_submenu_page('slb_dashboard_admin_page', 'slb_import_admin_page');
	//Hide "List Builder → Plugin Options".
	remove_submenu_page('slb_dashboard_admin_page', 'slb_options_admin_page');
}

add_action('admin_menu', 'plt_hide_snappy_list_builder_menus', 21);

Where do I put this code?