First create the item in Shop → Inventory with Add new item. Then go to Shop → Additional Items, click Add additional item and select it. The item shows at checkout while Active in the checkout is on.
Step 1: Create the item in Inventory
Go to Shop → Inventory.
Click Add new item.
Under Basic Details, enter the Name and Description.
Enter the Tax rate (%).
Enter the Inventory (stock). Leave it empty for unlimited stock.
Add an image under Images (optional).
Under Prices, set the Standard price and any cohort prices.
Click Save.
Step 2: Offer it at checkout
Go to Shop → Additional Items.
Click Add additional item.
Select the Inventory item.
Leave Active in the checkout on.
Set Maximum units per checkout if you want a limit (optional).
Under Options, turn on Refill inventory after session end time for items that come back, such as rental rackets (optional).
Turn on Special message in booking confirmation to add a message for players who buy the item (optional).
Under Day & Time Rules, limit when the item can be bought (optional).
Click Save.
Change the order at checkout
On Shop → Additional Items, drag the items into the order you want. Players see them in this order.
Good to know
You can't change the linked Inventory item after creating the additional item. Create a new one instead.
Price, tax, stock and image are always edited on the Inventory item, not on Additional Items.
Tax rate (%) does not fall back to your club's standard rate. If you leave it empty, no tax rate is sent to Stripe for the item.
Turn off Active in the checkout to hide an item for a while. It moves to Inactive.
Archiving an item in Inventory removes it from both pages.