Running ifplugd as root - trying to run script from it as non-root

Question

If am using ifplugd to monitor a LAN connection on an ubuntu 20.04 system which is acting as a router in addition to other things. When a cable is plugged in to LAN I want to launch a VPN session. I have been playing around with ifplugd and need to lauch a simple script to start protonvpn-cli to connect to a vpn server.

protonvpn-cli or a simple script containing it should run as regular user but it always executes as root.

I found this post very informative and thought the answers from @dessert were my answer too but it didn't work.

…
echo "Trying sudo -u meteor bash"
sudo -u meteor bash -c '\
  echo "$ whoami" && whoami && echo "^^^^^^ meteor expected"
  curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.6/install.sh |\
  bash
'
echo "ls -al /home/meteor/.nvm # should be populated"
…

For my situation I included the whoami output so I could see the non-root user was printed, but when protonvpn-cli executed it still warned me I was running as root user.

sudo -u regularuser bash -c 'whoami && "protonvpn-cli c -f" '

What am I doing wrong? I tried both methods in the referenced post above and they both behaved the same - whoami in the bash returns the regular user name but the protonvpn-cli executing returns the warning that I am running as root.