If you are specifically looking for version 3.3.10 for your Windows PC, you are likely using the dedicated WhatsApp desktop app. Unlike mobile beta programs, getting beta updates for the desktop client is generally a direct process. You can simply navigate to the official WhatsApp website and download the latest version from their servers. Please be aware that beta slots for desktop apps are often limited, so you may need to check for availability.
WhatsApp strictly prohibits the use of modified or unauthorized clients. If the WhatsApp servers detect that you are using an altered version of the app, your phone number could face a permanent ban. Whatsapp Beta 3.3.10 Download
Open your web browser and navigate to the on Google Play. If you are specifically looking for version 3