Integrate with my website...

Hello, I'm a web developer. I made a website for a client.

My client ask to make a shopping cart for he sell their products.

I can integrate zencart with the website that I made to my client?

Thanks

It is possible to have a product sales section with Zen Cart, inside a main site.
If you want to just use the back end checkout function for products already in the main site, that is not how Zen Cart is designed to work.
Ideally, Zen Cart is designed to be your whole site, with content pages alongside product pages so everything works seamlessly together. You can style Zen Cart to look like anything you want, if you are good with CSS, and HTML and PHP for more complex modifications.

Ok. Thanks...