Is there any print-on-demand (books) service that integrates with Squarespace?

Hello, I am looking for a print-on-demand service for printed books that I can integrate into my Squarespace store. I can't seem to find any online and apparently the Lulu API doesn't work with Squarespace. One workaround would be to get a Shopify store and then integrate that, but ideally I don't want to add an additional store just for this one service. Does anyone know of any other options? (Also I checked and Printful doesn't print books) Thanks!

As far as I know there aren't any at the moment. I wish there was. I wouldn't have to use the Son for my books.