thanks @sdetweil , right you are - I was not running npm from within the MagicMirror directory.
When I update ‘Display’ to 1 I still get an error when trying to manually run NPM, however when ‘Display’ is set to 0 and then I run NPM there are no errors with it. The error is:
pi@MagicMirrors:~/MagicMirror $ npm start
> magicmirror@2.10.1 start /home/pi/MagicMirror
> ./run-start.sh
(electron:11918): Gtk-WARNING **: 22:18:00.088: cannot open display: :1
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! magicmirror@2.10.1 start: `./run-start.sh`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the magicmirror@2.10.1 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! /home/pi/.npm/_logs/2020-02-04T22_18_00_154Z-debug.log
pi@MagicMirrors:~/MagicMirror $
@bhepler thanks for the link, it is a bit beyond my understanding at the moment. I will have to read up on it a bit more. I tried to run xrandr to see what kind of status it gives on the monitors but it currently comes back with ‘Can’t open display’, I assume it is because another service/application is utilising them?
Anyway, thanks for your help.