After you’ve completed a purchase, the download links for the item are automatically added to your Envato Market account’s download area. The download links you receive will include a Main File or Installation package and also the License Certificate which includes your Purchase Code.

To access your Purchase Code for an item:

1. Log into your Envato Market account.
2. Hover the mouse over your username at the top of the screen.
3. Click ‘Downloads’ from the drop down menu.`
4. Click ‘License certificate & purchase code’ (available as PDF or text file).

Source: https://help.market.envato.com/hc/en-us/articles/202822600-Where-Is-My-Purchase-Code-