Make sure you are using the standard E-junkie Cart button codes we provide in your E-junkie Seller Admin. Buyers would enter their discount code in the E-junkie cart before they proceed to checkout with PayPal. Do not use our "PayPal Cart" button codes, as those no longer work properly due to changes at PayPal's end, so they will be removed from the next version of Admin. The standard E-junkie cart will offer buyers a PayPal checkout button.
If you are using our Buy Now button codes instead of Cart buttons, those bypass the cart and take buyers directly to instant checkout for just one item at a time, so there is no chance to enter a discount code in the cart; however, certain types of discount code can still work if you use a special version of the Buy Now code that lets buyers enter a code on your page before they click Buy Now:
After the buyer completes checkout on PayPal's site, the buyer can click a Complete Purchase button to proceed to a thank-you page we generate for you. If PayPal has notified our system that they completed the payment by that point, we would present the buyer's unique download link(s) on that page; otherwise, we display a generic page instructing the buyer to watch their email for further information. Once PayPal informs us they completed the payment, we also issue the buyer a thank-you email with a link to reach the thank-you/download page in case they did not proceed to the download page after checkout.
Google Analytics (GA) is not really a conversion-tracking tool. It only tracks page-visit traffic statistics, as explained in more detail here:
Thus, the only way GA can "track conversions" is rather clumsily, by presuming that all buyers will visit a certain page after completing checkout. This is problematic with our service and PayPal in particular, as we cannot force them to auto-redirect anyone to any specific page after payment is completed, and their own Auto-Return setting would result in most download buyers being directed to a generic thank-you page rather than a page providing that buyer's unique download link. If ALL of your products are downloads, or if NONE of them are, we have devised some techniques for each of those scenarios to make the clumsy conversion tracking with GA less unreliable: