In the Store Edit, you can find the WhatsApp title under the Store tab
Whatsapp Number: Enter your WhatsApp number with the country code
Note : Please don't use space or special characters
Finally, Press the 'Save' button in the upper right corner to save the information.
Let see How your WhatsApp chat icon to display to the customer
Mobile browser view
Congratulations !!! Now your store WhatsApp chat is enabled for your customer, which will help your customers to engage with you easily.