Adding more codes
To add more codes to an existing discount set, you can easily do so from the dashboard. First, find the discount set in the list. You can change the list's sorting behavior and click through pages with the actions below the list. Once you've found the discount set you'd like to add codes to, simply hover over the row and click the Add codes action that appears. You will then be able to specify how you would like to add codes and the form will remember your last used settings.
If you need to change the details of the discount itself or would like to export all of the codes for a particular discount, you may do so from the discount details page within the Shopify admin through the "Go to discount" action on each discount set.
The Delete set action will remove the discount set from your list in the Bulk app, but does not delete the discount or codes from your Shopify admin to maintain your discount code functionality and reporting. If you would like to delete the codes so they no longer function, you may do so from the Shopify admin, but not within the Bulk app.