If you’re being asked for a “token”, then you don’t need a purchase code. A “personal token” or a “private token” (same thing) is an API key for the Envato API. You can generate a token here:
After you open that link, have a look at this screenshot, which shows all required permissions. Make sure you have the same boxes checked. Give it a name as shown in the screenshot, agree to the terms, and click the create button.
Enter the token it gives you into your theme (Enfold > Theme Update > Enter a valid Envato private token) and, as long as you created the token on the same account that you bought the item, it should work.
All this information is explained on Enfold’s help website at the link below. If you still have issues after performing the above steps, check out the troubleshooting guide at the bottom of their website: