How to Hide EventLoomix – Data Layer for Google Tag Manager Admin Menus

function plt_hide_eventloomix_data_layer_menus() {
	//Hide "EventLoomix".
	remove_menu_page('ategtm');
	//Hide "EventLoomix → EventLoomix".
	remove_submenu_page('ategtm', 'ategtm');
	//Hide "EventLoomix → Setup Wizard".
	remove_submenu_page('ategtm', 'ategtm-setup');
	//Hide "EventLoomix → Help  Documentation".
	remove_submenu_page('ategtm', 'ategtm-help');
}

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

Where do I put this code?