This is a 1.12.2 remake of the original Voltz pack.
This has a dedicated server built in. IP: mc.darkmatternetworks.co.uk:25571
Type in the modpack name (DMN: Volts Recharged ) or paste the following url into the search box.
Finally, click Install at the bottom right of the launcher after you select DMN: Volts Recharged from the list on the left. The launcher will handle everything else!