[SOLVED]PyQt5 tutorial

[Barrowman]

I am trying to see if I want to use PyQt5 and am working my way through some tutorials. I haven't got very far yet.
This one does not show the tooltip when I hover over the button. All I did was copy and paste from
https://zetcode.com/gui/pyqt5/firstprograms/

#!/usr/bin/python

"""
ZetCode PyQt5 tutorial

This example
e shows a tooltip on
a window and a button.

Author: Jan Bodnar
Website: zetcode.com
"""

import sys
from PyQt5.QtWidgets import (QWidget, QToolTip,
    QPushButton, QApplication)
from PyQt5.QtGui import QFont


class Example(QWidget):

    def __init__(self):
        super().__init__()

        self.initUI()


    def initUI(self):

        QToolTip.setFont(QFont('SansSerif', 10))

        self.setToolTip('This is a <b>QWidget</b> widget')

        btn = QPushButton('Button', self)
        btn.setToolTip('This is a <b>QPushButton</b> widget')
        btn.resize(btn.sizeHint())
        btn.move(50, 50)

        self.setGeometry(300, 300, 300, 200)
        self.setWindowTitle('Tooltips')
        self.show()


def main():

    app = QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())


if __name__ == '__main__':
    main()

QT version is 5.12.8
PYQT version is 5.14.1
Running Linux Mint 20.3 Cinnamon
Python 3.8.10