iOS 9.3.5’s Safari cannot load the modern WhatsApp Web (which requires WebRTC and modern JavaScript). However, you can use a third-party browser that includes a newer WebKit engine—but that’s technically impossible because Apple forbids alternate browser engines on iOS. Still, some browsers work better.
These apps don’t run WhatsApp; they connect to your phone via Wi-Fi and mirror notifications. You reply through the app using WhatsApp Web APIs. whatsapp for ipad 2 ios 935 updated
This is the most popular method among iPad 2 enthusiasts. You sideload an old version of WhatsApp (e.g., v2.19.80) that was the last to support iOS 9. whatsapp for ipad 2 ios 935 updated