On Ubuntu 20.04 - how to install WhatsApp Web?
Solution 1:
The app you require is Whatsdesk downloadable from the Ubuntu Software Center and has good reviews.
Solution 2:
You can use the snap store for this. Do:
sudo apt install snapd
Now restart your device.
sudo snap install snap-store
This should install the snap store on your device. It is GUI based and allows you to easily install whatsapp web. Or else, you can install using snap in terminal with
sudo snap install whatsapp-for-linux