Unable to install node-red - on raspian buster 2020-02-13

General
15

It seems I mis-spake slightly the first time. When I try to install I get

The following packages have unmet dependencies:
 nodered : Depends: npm (>= 5.8)

as did @Lupin_III but

apt policy npm
npm:
  Installed: (none)
  Candidate: 5.8.0+ds6-4
  Version table:
     5.8.0+ds6-4 500
        500 http://raspbian.raspberrypi.org/raspbian buster/main armhf Packages

so that is a bit odd. I would have thought that 5.8.0+ds6-4 should be considered > 5.8