If you run out of a particular product option, you can simply make it unavailable for some time in your app.
To make a product option unavailable, do the following:
Go to Locations > Shop > select your product.
(...)top right > press
Select the product option under the "Options" section.
Manage the "Available for Order" switch and hit
Saveto confirm your changes.
After making a product option unavailable, it becomes greyed out and it's not possible for users to get it.