You don't need the Purchase code if you've downloaded the theme on Envato Elements. You only need to register your Licence Item Code to use the theme. The purchase code is only needed for Automatic Updates and Support. Unfortunately, you are not entitled to them if you've downloaded the theme on Envato Elements. So to get a purchase code, support, and automatic updates, you need to purchase the theme on Envato Market. The version on Envato Elements is more suitable for developers/designers who don't need support and update the theme using FTP.