How to Hide Quttera Web Malware Scanner Admin Menus

function plt_hide_quttera_web_malware_scanner_menus() {
	//Hide "Quttera".
	remove_menu_page('quttera_wm_scanner');
	//Hide "Quttera → External Scanner".
	remove_submenu_page('quttera_wm_scanner', 'quttera_wm_scanner');
	//Hide "Quttera → Internal Scanner".
	remove_submenu_page('quttera_wm_scanner', 'quttera_wm_scanner_int');
	//Hide "Quttera → FAQ".
	remove_submenu_page('quttera_wm_scanner', 'quttera_wm_scanner_faq');
}

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

Where do I put this code?