Unable to create another node-red instance

need to ask one more thing. to have these instances auto started.

I need to edit nodered.service files present in locations :

/etc/systemd/system/multi-user.target.wants
/lib/systemd/system

edit lines -
existing
EnvironmentFile=-/home/scada/.node-red/EnvironmentFile
and adding below (referred link):
EnvironmentFile=-/node-reds/node-red-1881/EnvironmentFile
EnvironmentFile=-/node-reds/node-red-1882/EnvironmentFile
EnvironmentFile=-/node-reds/node-red-1883/EnvironmentFile (avoiding 1883 instance as suggested in the post)
EnvironmentFile=-/node-reds/node-red-1884/EnvironmentFile
EnvironmentFile=-/node-reds/node-red-1885/EnvironmentFile

Is this correct? Or is there any other way?