If you find a legacy version (like ) that still opens on your device, it will only offer "basic" functionality, and even this may be blocked by a "date too old" error or server rejection: About supported operating systems | WhatsApp Help Center
Use a mobile browser (like Chrome or Opera) in "Desktop Mode" to access your messages.
Upon installation, verify your phone number as you normally would. This step ensures you're using WhatsApp securely.
Look for "WhatsApp Plus" or "GBWhatsApp" legacy versions, though these carry privacy risks and potential account bans.