How can I use Pi-hole for all my devices except one (or more)?

OK - I thought I saw that in another thread here, where you could run the following to restart the service:
sudo systemct start pihole-FTL.service
(specifically it was this thread):

I tried running that command after saving the file quoted above as /etc/dnsmasq.d/04-bypass.conf, but it stated systemct isn't found either. Do i need to install that command on the pi?

I am running the commands via an ssh terminal connection from my Ubuntu laptop to the pi.

EDIT: I fixed the name I typed above for the filename (04-bypass.conf) - I forgot the zero.