How to Hide the "Email Encoder" Admin Menu

function plt_hide_email_address_encoder_menus() {
	//Hide the "Settings → Email Encoder" menu.
	remove_submenu_page('options-general.php', 'email-address-encoder');
}

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

Where do I put this code?