Help launching headless application?

Hey, I'm trying to do something that I assume is pretty basic - create a barebones Unity application and launch it in headless mode (server build) on OSX. Unfortunately, I'm pretty lost.

I have a new Unity (2019.2.2f1) file with a single game object in the scene, which has a script attached:

 public class test : MonoBehaviour {
     void Start() {
         Check();
     }
     void Check() {
         if (Application.isBatchMode) {
             Debug.Log("In BatchMode");
         } else {
             Debug.Log("not in batch mode");
         }
     }
 }

This works fine when running in Unity, and after building it as a Server Build targeted at Mac OX X, I have an .app file. The problem is, I'm not sure where to go from here. How do I actually run this file? And what should I expect as a result? Things I've tried:

• Double clicking on the file... it'll launch, go into not responding mode, and close after a while
  
  

• Running "open testbuild.app" from the terminal, same result
  
  

• While Googling, I found the command line arguments. The first one simply opens Unity Hub; I'm not sure how you'd go about opening a specific Unity file. "testbuild.app --batchmode" and "testbuild --batchmode" return "command not found."
  
  

• Following the steps here, I ran "chmod 755 testbuild.app" and then "./testbuild -batchmode", but got back an error saying that testbuild.app is a directory.
  
  To make matters tougher, I'm not sure what kind of output I am expecting. I read that headless builds will save output in the Log files, but I didn't see anything relevant there.
  
  I really appreciate the help. I've been trying to figure this out all day but haven't really made any progress.
  
  Thanks in advance!
  
  P.S. my overall goal is to eventually build a server that I can deploy on a VPS. After I get this working, My next step is launching a server when headless mode is detected.