On Thu, 1 Aug 2019, Brian wrote:
The plugin can be downloaded from https://www.openprinting.org/download/printdriver/auxfiles/HP/plugins/
   after waiting several minutes, I get:
      this site can't be reached ... timed out
and installed with the -p option of hp-plugin.
    and this gives, as usual:
   error: Unable to open /home/frenkiel/.hplip/hp-plugin.lock lock file.
best regards,
--
Pierre Frenkiel