In order for you to Create Development Environment for Web Site for CometChat. Please follow below Steps to Setup Development Environment for your Web Site
Create one subdomain for your website such as 'development.abc.com'.
Now login to FTP Account using root user and create 'development' folder in root directory. Once it is done Transfer all your website files in this 'development' folder.
Now using your hosting panel map 'development.abc.com' to 'development' folder.
Using hosting details Create New Database for development. Database name will be 'development'
Transfer all your sites table into 'development' database.
Make Changes in your Site Configuration & Database Configuration File. Check if your website is working properly.
Once Done Create new Credentials for FTP, Database, CPanel and provide to us so CometChat team Will proceed with CometChat Installation on your WebSite.