You can initiate a call to your contact from WhatsApp Web to your phone instantly with InTouchApp Extension.
Before you proceed, you need InTouchApp installed on your phone & InTouchApp Extension installed on Chrome or Firefox. Learn more.
How to Initiate a Call from WhatsApp Web to phone:
Step 1 - Open web WhatsApp in the browser and Scan the QR code by using WhatsApp.
Step 2 - Go to the contact you want to call.
Step 3 - On the top right side of the Chat screen on the Options bar, you will see a red Callicon - Click on the same.
Step 4 - Open your phone's dialer and you will see the contact number automatically placed there. Now go ahead and call the person.