Before you proceed, you need InTouchApp installed on your phone & InTouchApp Extension installed on Chrome or Firefox. Learn more.
How to Add new Contact from WhatsApp Web:
Step 1 - Open web.whatsapp.com in the browser and Scan the QR code by using WhatsApp on phone.
Step 2 - On the top left of the screen, beside the display picture, click on a red plus + icon > select Add new contact.
Step 3 - Enter the details you want to about the contact. When done, click on Save Contact.
The contact gets automatically saved in your phone contact book.