What this video covers
Every setting in the Discount & rewards step of a subscription plan. First the plan discount: Amount (a percentage, a dollar amount or a fixed price) and Apply to (Every order, First order or Change later). Then rewards: the five reward types (Percentage off, Amount off, Fixed price, Free gift and Shipping price), Reward starts on, the free gift and shipping price options, Include in the repeating pattern, and Who gets this reward, with conditions joined by and or or. Last, the store setting Keep free products while a paid product in the order uses the same plan, the Product page, Customer portal and How it works previews, and your store's product page with the subscription price and saving.
In short
Open the plan, click Edit on the subscription option, then choose Discount & rewards.
The plan discount comes first. Each reward starts on the order you pick, and a Percentage off or Amount off reward is the total discount for its orders: it replaces earlier discounts instead of adding to them.
A free gift goes in one order. A Shipping price reward lasts until the next shipping price reward, or for one order only with Only this order, then back to the normal shipping price.
If Add a reward or a reward type is locked on your store, the reason shows right there.
Click Done to keep your changes, then save the plan to put the plan discount live. On an option that's already saved, Done saves reward changes right away.