You may already have FileMaker Server up and running with a host available for use with LCFM Native. If you do, simply enter your FileMaker Server address in the appropriate field. You should use the domain name format and omit the "http" part. So if my FMS address is https://myserver.myfilemakerserver.com I would enter myserver.myfilemakerserver.com.
If not, you can set up a test environment by installing FileMaker Server on your computer and setting it to use localhost. Here's how.
Go to System Preferences on your Mac, and open the Sharing panel.
At the top of this screen, you will see your localhost address: mine is Heathers-MacBook-Pro.local.
Open FileMaker, and go to File>Hosts>Show Hosts
Click the + next to Search Hosts
Enter your localhost address in the address field (1), and optionally a name for it in the name field (2) and click Save (3).
Your host is now set up and ready to use with LCFM Native.
To get your Server Address to enter in LCFM Native, log in to your console here:
Your server address is on the Dashboard.