Location preferences file location in Catalina

[smartarts]

I had an iMac with Mojave and for some time I have needed to change the network location to get the internet connection to work at startup

At some stage I accidentally removed the "Automatic" location setting.

I have now a new iMac with Catalina

I populated the new Catalina iMac with the contents of Mojave machine.

Now Automatic is still missing for the Network setting

& I still need to create a new location for time to time



so...

2 questions

1. Is "Automatic" just a name (same a a created new one) or is it some kind of special location setting

2 Is there a preferences file that controls the locations?

I tried removing and re creating a new wi-fi network but the Locations did not re-set

I'd like to remove or replace that preferences file (I have a copy of preferences form a fresh instal of Catalina)