Access “WhatsApp configuration” from Settings > Other Settings > WhatsApp configuration >Gear Icon 
This is the setting page to manage various activities of WhatsApp within vTiger.
- Add/Remove modules to be integrated with WhatsApp to Send/Receive messages against any phone number of the module.
- In “Access modules to WhatsApp” click on
to add modules to provide access to display WhatsApp icons to send/receive WhatsApp messages.
- Select “WhatsApp # field” field from “Access modules to WhatsApp” to allow which fields in selected modules to be considered as WhatsApp fields.