sell as an isbn through LuLu distribution guide?
ref: https://reportagebook.com/, https://readmake.com/, whop, https://inteltechniques.com/book8.html
btcpayserver, knots + electrs server, wallet, core-lightning, amboss/zeue lsp.
advertize buyers to use cake-payjoin.
joinstr.xyz pools?
support cards via bankcardusa/nmi/pst.
xPayments?
You may generate a copy of the book in bookdown::pdf_book format by calling bookdown::render_book('index.Rmd', 'bookdown::pdf_book').