My first children's book released on Friday. I used Amazon's KDP print-on-demand service. It's not terribly difficult but there's definitely a learning curve with it. Theoretically you could bulk order author copies to sell for sats, but then you're in charge of fulfillment.

I think IngramSpark may integrate with something like shopify to accept bitcoin? I wanted to get this first book out, so I stopped researching all the options available so I would actually get it into the world.