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The PLU item needs to exist in the restaurant PLU data (PLU with price)
If the item doesn't exist in the selected store data (when using the Whitelabel app) the app will alert the user that the item is unavailable (when the item is added in the cart preview or added inside the checkout, for example)
The restaurant data is not available to be configured inside Sanity. This needs to be done somewhere else (perhaps, where we configure the POS data for restaurants)
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