If your Windows Phone has a MicroSD card slot (common in Lumia 520, 640, 830, etc.), this is the easiest method.

You will need a PC with the Windows Phone 8.1 SDK installed. XAP Deployment Tool: This is usually included with the SDK. Steps to Install:

If you still wish to experiment with sideloading on older devices, you can find archived versions from third-party community sources: Windows Phone App Archive (Reddit)

If you are a collector or researcher and still wish to find these files for archival purposes, they are sometimes hosted on community-driven repositories: Windows Phone Archive (Windows Việt) : A known repository for original .appxbundle files for Lumia devices. Archive.org (Windows Phone Store Page)

– The WhatsApp icon will appear in the app list. Launch it.