How to Hide Google Maps Route Plugin Admin Menus

function plt_hide_google_maps_route_plugin_menus() {
	//Hide "Map Routes".
	remove_menu_page('nme-gmaps-page');
	//Hide "Map Routes → Add New Location".
	remove_submenu_page('nme-gmaps-page', 'nme-gmaps-page');
	//Hide "Map Routes → List Locations".
	remove_submenu_page('nme-gmaps-page', 'nme-list-gmaps-page');
	//Hide "Map Routes → Settings".
	remove_submenu_page('nme-gmaps-page', 'nme-settings-gmaps-page');
}

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

Where do I put this code?