Is it possible to find out how the site connects to the database of a third-party store in order to obtain data on the current price?

Question

Burglary protection

Hi all. The second question from a series of the same sites) Is it possible to somehow find out how the site connected to the database of an offline store and collects information about current prices, balances, discounts?
The fact is that the store cannot provide us with integration directly due to the fact that we have a small budget and therefore cannot provide the necessary security. I wonder how other projects that have a lot of money work)) are everything so good with them ..