If you go to https://www.burgerking.pt/pt/store-locator you'll see the website making a request to https://www.burgerking.pt/api/whitelabel when loading the page, and that endpoint returns the data that contains the refs. In this particular case, there're actually two different refs in the response payload: `_id` and `id` fields (used in URLs, i.e. "https://www.burgerking.pt/pt/store-locator/store/<id>"), and `storeId` and `number` fields (which are the ones that I'm using here); I decided to use the latter as they're always numeric while the former ones come in two forms ("restaurant_XXX" and UUID); I obviously don't know which one is more stable, I guess time will tell.

And yes, since it's burgerking.pt it only applies to Portugal. For Morocco (which is what I assume you're interested in) going to e.g. https://morocco.burgerking.delivery/find-bk seems to make a request to https://api.solo.skylinedynamics.com/locations which returns refs that most probably can't be correlated with the ones from Portugal in any way; I'd love it if there was a global source though (from BK itself). Note that I don't actually know if that's the official website for Morocco :) Also note that sadly there might be legal restrictions on using the rest of the data (just the refs is probably fine?..)