If you were not prompted to add your Auth Key during your WordPress CometChat Plugin installation, it is possible that the Basic Security features of CometChat are not enabled.
Before you begin, Sign in to your CometChat Client Area and click on the Manage button and then note down the Auth Key present in API Keys (top right button).
Then perform these steps to enable Basic Security
Ensure your WordPress CometChat Plugin is equal or greater than 7.27.3
If you have an older version, you can download and install the latest version. (You may have to delete the older plugin.)
Download the CometChat WordPress Plugin Zip File