How to upgrade cv2 from 4.2.34 to 4.3.0

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UBUNTU 18.04, Python 3,

I am working on a image processing task which has a cv2 module name dnn_superres

and I am unable to import the below module

from cv2 import dnn_superres

It would work on cv2 4.3.0

my current version is cv2 4.2.34

Kindly help how come I upgrame my cv2 from 4.2.34 to 4.3.0

Thanks