Enabling one-time discount codes
By default, Restrict Content Pro applies discount codes to all payments within a subscription, not just the first payment. For example, if a customer applies a 30% discount to a $10 subscription, the customer’s initial signup payment would be discounted to $7 and all renewal payments after the first payment would also be $7. There is an option to change this behavior and make discount codes apply only to the first payment in a subscription.
Navigate to Restrict > Settings > Misc and check the box to enable "One-Time Discounts".
When enabled, all discount codes will apply to the first payment only. Using the same example as before, if a customer applies a 30% discount to a $10 subscription, the initial payment would be discounted to $7 but all subsequent payments would be for the original $10 amount.