Domain is not whitelisted for this deployment Salesforce Chat Exception is thrown since the Site Referrer is not configured properly on the Chat Deployment.
1. Go to the Webpage where the Salesforce Chat code is hosted.
2. Right Click on the browser and select Inspect.
3. Reload the Webpage.
4. On the Browser Network tab, find the Settings.jsonp for Embedded Service Chat.
5. On the Headers tab, check the “Referer”.
6. Make sure the “Referer” is added in the Chat Deployment Permitted Domains properly.