Those are called Chicago Screws. I don’t know where you are so can’t really recommend anyone, but that kind of book is pretty easy to make; I bet you could figure it out yourself if you need to. Look up bookbinders in your area though.
Hi Michelle, thanks for your comment. If you have a regular book block that’s bound with glue or sewn to tapes (or both), you would glue endpapers to the inside covers and first/last page of the book, and these hold everything in place. You just need to make the spine wide enough to accommodate the depth of your book block.