I made a working 64bit sfs version of hplip which is HP's comprehensive linux CUPS driver package.
Tested and used extensively with my HP Officejet Pro 9020, working flawlessly in Fossapup64. Simply mount the sfs and the drivers show up in CUPS when adding or managing a printer.
hplip.sfs can be found here:
https://mega.nz/file/vXpWBbZD#ZtycHGfAO ... VXVugS6ChI
md5 hash and other sfs files found here:
https://mega.nz/folder/reoShDjA#ONbUYMfog9J7AWe9RVe2Uw
Thanks to all who helped me with scripts, especially @mikeslr
Let me know if you try it, how it works in different puppy versions.