Running Multiple Instances of Node-red using NSSM

General
2

Assuming you setup your folders like described in that thread (a few posts above the one you linked to) (this post) then you would set your NSSM commands to run each instance in the same way as if you were running it from a cmd window

example...

NSSM1: node-red -p 1880 -u c:/node-red-1880
NSSM2: node-red -p 1881 -u c:/node-red-1881
NSSM3: node-red -p 1882 -u c:/node-red-1882

etc etc

Just be sure that the account that runs the NSSM service has read/write access to these folders.