If you have a password protected proxy endpoint chrome does not unfortunately support that so you can simply run transparent proxy in between
for usage please run transparent_proxy --help
sudo cp com.nefthias.transparent_proxy.plist /Library/LaunchDaemons &&
sudo launchctl load /Library/LaunchDaemons/com.nefthias.transparent_proxy.plist
sudo launchctl unload /Library/LaunchDaemons/com.nefthias.transparent_proxy.plist &&
sudo rm /Library/LaunchDaemons/com.nefthias.transparent_proxy.plist
sudo launchctl start com.nefthias.transparent_proxy
sudo launchctl stop com.nefthias.transparent_proxy
sudo launchctl restart com.nefthias.transparent_proxy
sudo tail -f /var/log/com.nefthias.transparent_proxy.log