I am trying to set up WhatsApp on my computer (Mac running OS X El Capitan version 10.11.6). I am told to "select WhatsApp Web" in my iPhone settings. But there is no "WhatsApp Web" anywhere. The iPhone is running iOS 11.3.
Browse to https://web.whatsapp.com/. You should see something like the following, with a QR code at right:
Open WhatsApp on your phone
- Go to Settings->WhatsApp Web/Desktop
- Scan QR code with your phone