for example, I have a simple website where there is a list of posts, they are of two types: paid and free, paid ones can be purchased by authorized users and then they can read it, free ones can be read by anyone, after registration, all authorized users will have their own balance, there will be a payment system, and each authorized user can deposit at least 5$, after payment, so that the amount he deposited will be credited to his account, how can I implement this and what technologies do I need to use and what should I pay attention to?