Unfortunately the Q&A you are consulting is
Mostly obsolete, since the accepted answer uses SysV init style methods instead of systemd ones. These are both init systems. The former is used on v. <= 7 Raspbian (unless I am remembering wrong, there's actually no < 7 since Raspbian follows Debian version numbering, and Debian has been evolving for a few decades). The latter is used on the previous (8, jessie) and current (9, stretch) versions. It supports SysV scripts for backward compatibility, but...
The accepted answer in that Q&A does not actually explain how to write a SysV style script, just how to enable one. And that's why you get the "missing LSB tags" error. The script is missing a lot of things that would make it SysV compliant.
There's no point in learning how to write such a script, however (it is a bit ornate), since the system is obsolete.
The easiest thing to do there would be to just add something to the end of
/etc/rc.local (but before the final
exit 0 line):
cd /media/root/NEW\ VOLUME/FurBot
setsid node bot.js &> /dev/null
Notice I inverted the slash in
NEW\ VOLUME. Command line parameters cannot have unescaped spaces in them; I presume that's what you mean to do. You can instead use quotes:
cd "/media/root/NEW VOLUME/FurBot"
setsid maybe spurious here but doesn't hurt. See
man setsid for what it does.
If you want to get fancier, you can write a systemd service file for it --
you will find a lot of examples of such for
node.js online -- but if this works for you, then don't worry about it.