Qt for Python (PySide/Shiboken)

To add a new python interpreter, you use the "Manage" button in the run configuration of a Qt for Python project. There you can provide the path to the python executable, and give it a name. Then you can select it from the dropdown list of interpreters. Note that the Python environment you select still needs to have PySide6 installed - Qt Creator doesn't install it for you, so, from a command line, install it using pip: /path/to/your/python -m pip install PySide6