Do I need to open a company to sell applications?

Question

Programming

Slowly, I’m still sawing apps for sale, with a friend. At the beginning, there was an idea to sell everything on CodeCanyon, but it scares a little with a commission, there was an idea to make a landing page for each product and attach a payment system. In general, while everything is still at the initial stage, we are still thinking how best to implement it.
The question is different. Do I need to open an IP or as they are called Sole Trader in England. What are the risks that someone will find me on the Internet and find out that I am especially eager to pay taxes? As I understand it, if you work through CodeCanyon, there is a withdrawal to PayPal, and it is easier to write off money with PP, and the same purchases can be paid on the Internet, i.e. not much of a problem. The question is, what if we decide to sell ourselves, on our own website, on the same Stripe? What can really threaten us?
Let's say there is no experience in developing and selling products, that's why I'm asking for advice. Thanks