qrcode detector not in cv2

[Pedroski55]

I am just following the instructions here, trying to learn how this works.

I am now trying to read a qr code I made.

this shows no errors:

# read the QRCODE image
img1 = cv2.imread("myQR_blue.png")

But this does not work:

# initialize the cv2 QRCode detector
detector = cv2.QRCodeDetector() # whoops, doesn't work!

I get this in Idle:

>>> detector = cv2.QRCodeDetector()
Traceback (most recent call last):
File "<pyshell#20>", line 1, in <module>
detector = cv2.QRCodeDetector()
AttributeError: module 'cv2' has no attribute 'QRCodeDetector'

The webpage says it was updated September 2020.

I installed cv2 from Ubuntu: sudo apt-get install python3-opencv

How do I get the detector?