Creating an online casino with CAD GPT involves several steps. First, you'll need to generate HTML code using CAD GPT for the basic structure of your casino, including a header, payment section, and footer. Next, you'll use Visual Studio Code to create a new folder and HTML file for your casino app, where you'll paste the generated code. You'll then customize the HTML with images, game previews, and additional pages for login, registration, and individual games. For the games, you can use iframe links to embed demo games from providers like Pragmatic Play. Finally, you'll need to style your pages and potentially add server-side scripts for functionalities like login and registration. Remember, this is a basic structure and further development and legal considerations are required to launch a real online casino.