Ran into an article on Liliputing that stated that from June, 2024 on you won't be able to purchase new content from the B&N store, register a new B&N account, or sign into devices with a NOOK account on all 2013 and older Nook ereaders and tablets.
Original article is here:
B&N is ending support for NOOK eReaders & tablets from 2013 and earlier