There is a new post by Google My Business in their help documents that talks about a new pilot program that gives some businesses the ability to chat with their customers directly via the local knowledge graph panel.
For those businesses that are able to utilize this feature will see a new “message” button added to their local listing on Google when you’re in this test feature. The message button initiates a chat between your business and the searcher. According to Google, “Google My Business allows you to chat directly with customers who find your business listing on Google Search.”
Google sent some businesses emails “inviting you to participate in the pilot.” If you didn’t receive in a invite, you an’t access this feature.
chek ot the image below of the message button in the local panel on Google:
The messaging goes through the businesses’ SMS number or via Google Allo.
For more details on this, please check out the Google help document.