Open Safari on your iPad
Go to web.whatsapp.com
If the WhatsApp page opens in mobile view, tap the aA icon in the address bar
Select Request Desktop Website
Open WhatsApp on your phone
Tap Settings or Menu
Tap Linked Devices
Tap Link a Device
Scan the QR code shown on the iPad with your phone
Keep your phone connected to the internet for syncing
Use WhatsApp from the iPad browser
For better access, add the page to your Home Screen from Safari share options