If you are connected via an API, you can control the availability through your system. Otherwise, you can go to the Sales Calendar in the Supplier Portal and close dates or time slots as needed. There is also an option to refund existing orders. You can find the details about the Sales Calendar here.
Select the product you would like to change in “My Listings” to edit your availability and capacity as required. If this is not available yet, or you don’t have access to it, please contact email@example.com.