Error app javascript, shop token is empty

[Castelblanco]

Good morning, I have a problem with my app that is related to the shop_token of a store, my app reads categories, products, customers and orders to display them in an interface, but for this we use a shop_token provided by shopify, the problem is that sometimes sometimes the shop_token arrives empty instead of bringing the shop_token as it should, I would like to know what are the possible errors or occasions in which this happens. Or sometimes shop_name and shop_token are from other shops in my partner account

I await your response, thank you.