1. Open Safari on your iPad → head to web.whatsapp.com

2. Now, open WhatsApp on your iPhone.

3. Tap Settings at the bottom right corner. 

4. Select Linked Devices → tap the Link a Device option. 

5. Authenticate yourself using Face ID, Touch ID, or Password. 

6. Now, your primary device will open the Scan QR Code page. 

7. From this page, scan the QR Code displayed on your iPad screen 

8. WhatsApp Web will download all your messages, and once the loading bar is completed