Sort:  

You should install Qt designer firstly.

I already installed Qt

https://drive.google.com/file/d/1vk4NdwbCJ5agVBkOarV7vFLfwBRj7e1Q/view?usp=drivesdk
Try with this version of thonny, it contains all the libraries we need: pandas, matplotlib, numpy, pyqt5, ... ==> Full version (windows 10 or more)
Good work to all.

Alright I try with this.

image.png

I am still Facing this problem.

image.png

Its not upgraded

Install pyqt5-tools also.

On PyQt5-tools

image.png

If you’re on a restricted network (such as a school or corporate network), firewall settings may block SSL verification. In such cases, check with your network administrator.