How to Hide Sessions Admin Menus

function plt_hide_sessions_menus() {
	//Hide "PerfOps One".
	remove_menu_page('perfopsone-dashboard');
	//Hide "PerfOps One → Control Center".
	remove_submenu_page('perfopsone-dashboard', 'perfopsone-dashboard');
	//Hide "PerfOps One → Tools".
	remove_submenu_page('perfopsone-dashboard', 'perfopsone-tools');
	//Hide "PerfOps One → Analytics".
	remove_submenu_page('perfopsone-dashboard', 'perfopsone-analytics');
}

add_action('admin_menu', 'plt_hide_sessions_menus', 111);

Where do I put this code?