How to fix ModuleNotFoundError: No module named 'PySide2',

Question

The am using docker container ubuntu 18.04, I have installed python 3.7. The program works on ubuntu 18.04 with GUI. I am facin the following error: ModuleNotFoundError: No module named 'PySide2'

I have tried installing it by running: pip install PySide2 But this is the error I get:

Defaulting to user installation because normal site-packages is not writeable
ERROR: Could not find a version that satisfies the requirement PySide2 (from versions: none)
ERROR: No matching distribution found for PySide2

I have also tried: pip3 install PySide2 But still get the same error:

Defaulting to user installation because normal site-packages is not writeable
ERROR: Could not find a version that satisfies the requirement PySide2 (from versions: none)
ERROR: No matching distribution found for PySide2

I was initally using python 3.8. But read somewhere that it does not suppose it. So I installed python 3.7. I have got the same error with python 3.6 and python 3.5

I have also adding --user , that is, pip install PySide2 --user and pip3 install PySide2 --user I still continue to get the same error.

ERROR: Could not find a version that satisfies the requirement PySide2 (from versions: none)
ERROR: No matching distribution found for PySide2

I have also tired sudo apt-get install PySide2 Then I get this error:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package PySide2

I even tired installing the wheel directly from https://www.lfd.uci.edu/~gohlke/pythonlibs/#pyqt4

and then run it. It doesn't work.

I would really apprecite if someone can help me out here!