Who is paying for the 1000s of Kamala Harris-authored books that are being given away to immigrants?

Superheroes are Everywhere! Read more here: https://pjmedia.com/news-and-politics/victoria-taft/2021/04/26/kamala-gate-the-white-house-responds-to-growing-scandal-over-giving-away-vps-book-to-illegal-aliens-n1442836