What's the difference between subscription discounts and discount codes created in Shopify?
Subscription discounts are configured in your subscription group settings and automatically applied to orders. Read more about subscription group discounts in Subscription Group Settings.
Discount codes are created in your Shopify admin and can be added in the checkout or customer portal. Shopify discount codes can be used alone or together with subscription group discounts. Read more about these in Discount Codes for Subscription for Shopify Checkout.