How to open a second window in PySide2?

Question

Python

In general, I am writing a program in PySide2, I have 3 files - main.py, uisettings.py, uimain.py. It's not hard to figure out what's what.

I write all the logic in main.py, the rest of the files were created using pyuic2

uimain is called after the program starts, there is a button on it that should launch the second window and turn off the first one. How to do it right and without crutches?