To publish The Booking Form on your website you need to go to Dashboard > Get the code and Copy the code by clicking on "Copy the code" button.
You can customize your "Book now" button's look and feel to blend with your website or to look like an inviting Call-to-action button. Learn details about how to customize your "Book now" button here.
Then go to the HTML of your website (most CMS websites allow you to view the HTML via their text editor eg. "View the code" or similar button) and paste the code you have copied earlier.
Alternatively, you can just copy the link to your booking form and use it anywhere on your website to send people to make a booking.