Use APKPure App
Get Beta Updater For Whatsapp old version APK for Android
Get Beta WhatsApp app to update to the latest version of WhatsApp for Android.
Download WhatsApp Updates app (New) to update to the latest version of WhatsApp for Android..The app checks the latest beta version available on whatsapp.com and enables you to install it automatically.
WhatsApp publishes beta updates on their website before they become available on Google Play. This means that the latest features aren't available on Google Play until several weeks later (like audio calls, backup to Google Drive and new UI changes).
When a user wants to have these beta updates, the regular method is downloading the APK file from the website and installing it manually. Beta Updater does that automatically.