Program development, with a paid version?

Question

Python

Such a thing, I decided to try to write programs for engineering calculations. I want to write a program with a trial period, and after the trial period expires, I want to ask for finances (purely symbolically), the user will have to enter the card number, CVV, and expiration date (I don’t know how legal it is, well, let’s omit it, it’s not the point), but the program will automatically have to send the activation password, which is entered into the config file and the program continues to work. So, the question is how to implement this in python, modules, APIs, libraries, etc. I will be glad to advice and help.

Answer 1

You raise a server where you implement a useful part of the functionality by accessing the API.
Attach some external payment to the program

I don’t know how legal it is, well, let’s omit it, that’s not the point

It is quite legal if the client will be transferred to the bank's website for payment and he will enter all payment details there.
On the same server, record the fact of the client's payment and the validity period of the payment. Submit API data if payment has not expired.
That's actually all...