Raspberry pi install script fails with valid node.js but without npm installed

[peeter123]

When I run the script with a valid node.js install but without npm installed, the installer script fails.

Terminal output:

This can take 20-30 minutes on the slower Pi versions - please wait.

  Stop Node-RED                       ✔
  Remove old version of Node-RED      ✔
  Remove old version of Node.js       -
  Leave existing Node.js              ✘   Failed to install Node.js - Exit
  Clean npm cache
  Install Node-RED core
  Move global nodes to local
  Install extra Pi nodes
  Npm rebuild existing nodes
  Add shortcut commands
  Update systemd script

Any errors will be logged to   /var/log/nodered-install.log

nodered-install.log:

Running for user pi at /home/pi
Found global nodes:   :

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

Reading package lists...
Building dependency tree...
Reading state information...
Package 'nodered' is not installed, so not removed
The following package was automatically installed and is no longer required:
  dc
Use 'sudo apt autoremove' to remove it.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Already have nodejs v10.19.0
Now install nodejs

[dceejay]

updated - please try now. thanks