Meta (formerly Facebook) discontinued the Windows Phone app years ago and replaced it with a web-based client for modern PCs. Alternatives for Windows Phone Users
When WhatsApp announced the end of support, Microsoft delisted the app from the store. There is no official "WhatsApp XAP download link" hosted by Meta (Facebook) or Microsoft anymore. Trying to download WhatsApp from the Store on your device will result in an error: "This app is no longer available." whatsapp xap download link