Once this is done, your account will be paired and you will be able to use it on Windows, even without any Internet connection on your smartphone, since WhatsApp Desktop Beta works independently.
After installing it, you will have to scan a QR code through the WhatsApp app on your smartphone. WhatsApp Desktop Beta works in the same way as the normal version. With it, you will have the opportunity to try out the latest features of the Windows app before they reach the stable version.
WhatsApp Desktop Beta is the beta version of the official WhatsApp Desktop app.