How to Hide GSpeech Admin Menus

function plt_hide_gspeech_menus() {
	//Hide "GSpeech".
	remove_menu_page('gspeech');
	//Hide "GSpeech → Dashboard".
	remove_submenu_page('gspeech', 'gspeech');
	//Hide "GSpeech → Cloud Console".
	remove_submenu_page('gspeech', 'gspeech_cloud_console');
	//Hide "GSpeech → GSpeech 2.X".
	remove_submenu_page('gspeech', 'gspeech_2x');
	//Hide "GSpeech → FAQ".
	remove_submenu_page('gspeech', 'gspeech_faq');
	//Hide "GSpeech → Contact Us".
	remove_submenu_page('gspeech', 'gspeech_contact_us');
	//Hide "GSpeech → Upgrade  ➤".
	remove_submenu_page('gspeech', 'gspeech_upgrade');
}

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

Where do I put this code?