Disable auto-update in Play Store (Go to WhatsApp page > Three dots > Uncheck "Enable auto-update"). Also, block WhatsApp’s access to Wi-Fi/mobile data for update checks using a firewall app like NetGuard.
Once you have the APK file on your device, you can share it with others: go share whatsapp link download old version
Go to your phone’s (or Apps) and enable "Install Unknown Apps" for your browser. Disable auto-update in Play Store (Go to WhatsApp
If you are ready to proceed, follow this exact method to download and install a compatible old version of WhatsApp. Three dots >