Which GUI library to choose and what language to write in?

Question

Python

Hello Toasters!
I am writing a program (in cpp and python) and I need a good GUI editor that is free / takes % from the proceeds / not expensive. I do not want to distribute the program code (and it's a shame to show the "top" code). The program itself will be distributed free of charge, a subscription and dls will be sold. Prices will be based on Russians, purely pay for the server that would be enough. A simple design in me will kill the designer, so the maximum functionality is desirable.
I jumped on a lot of things, stopped at QT. A good thing, not without jambs, but they fade before the functionality (QML for example). The problem is in the licensing on the free version. There is no license to buy ($459 each month, CARL!) for the program.
I saw a lot of Python GUI libraries, but most of them are written in Qt (logically, you still need a license for it, but I didn’t find any information for sure).
If there is something like Unreal in the world of dectop GUI editors, please tell us. Or, if you have something useful, please share. I'll try to repay you in full for the help.

Answer 1

Popular libraries and lessons for them:
wxPython (54 lessons)
https://python-scripts.com/wxpython
Tkinter https://python-scripts.com/category/gui/tkinter-python
PyCairo https://python-scripts. com/category/gui/pycairo-tu...

Answer 2

https://www.ultimatepp.org/index.html

Answer 3

I can recommend Avalonia Ui /C#.