What do the Importing and Queued statuses mean?

After creating a new discount set, or adding codes to an existing one, your discount set will update to either Importing or Queued statuses.

Importing - This discount set is actively importing the codes into your Shopify admin. After the estimated generation time, you should expect to see the codes available in the Shopify Discounts. Please note that the generation time is only an estimate and may vary.

You can find an import badge on the dashboard that updates you on the import status. 

Queued - Due to rate limits in Shopify's API, the app will only import one discount set at a time. Queued signify the discount set is waiting to import the codes into Shopify. You will only see this status if there's already an existing discount set in the Importing status. Queued imports will run in the order that they were created.