To add games to your online casino website, you'll need to create individual HTML pages for each game. On these pages, you can embed the games using iframes if you have the necessary permissions from the game providers. Each game page should include the game's title and an iframe linking to the game's playable version. Ensure that the iframe has the correct dimensions and is styled with rounded edges if desired. If you're using games from providers like Pragmatic Play, you can use their demo codes for demonstration purposes. Remember to check licensing and legal requirements before adding real-money games to your casino.