The repository lists a one-click deployment section with buttons for hosting platforms, next to fork and star links. Pairing a WhatsApp account and deploying the bot source code are two different processes: pairing links your number to a running server, while deploying means running your own copy of the code.
If you deploy it yourself, review the README, the source code, the dependencies and the license first. Set up the required configuration and environment variables as the current documentation describes, and link a WhatsApp account only after you understand how the deployment handles sessions.
A GitHub fork is a copy of the source code, not a running bot. A deployment still needs a compatible runtime, correct configuration and enough hosting resources to stay online.