Easy Digital Downloads Discount Code Generator:
The Easy Digital Downloads Discount Code Generator allows site admins to generate discount codes in bulk. They can also then export them directly to CSV. You can also generate an unlimited number of discount codes and control the exact options for the discount codes that are generated. This also includes required products, minimum amounts, one-time use, etc., just like standard discounts in Easy Digital Downloads.
After discounts are generated, you can then export them as a . CSV file, simply by pressing a button.
Also, if you need to import discounts in bulk, you can have a look at the CSV Coupon Importer extension.