Jmeter is not running the HttpSamplerProxy

I am running this with jmeter core and jmeter http both at version 5.3. I am confused to why the sampler will not fire off. I am new to using jmeter in this fashion and am not quite sure how this all works. When the code is ran i end up with no request data in the jtl file.

        //JMeter initialization (properties, log levels, locale, etc)
        JMeterUtils.loadJMeterProperties(System.getenv("JMETER_HOME") + "/bin/jmeter.properties");
        JMeterUtils.initLogging();// you can comment this line out to see extra log messages of i.e. DEBUG level
        JMeterUtils.initLocale();

        // JMeter Test Plan, basic all u JOrphan HashTree
        HashTree testPlanTree = new HashTree();

        // HTTP Sampler
        HTTPSampler httpSampler = new HTTPSampler();
        httpSampler.setDomain("example.com");
        httpSampler.setPort(80);
        httpSampler.setPath("/");
        httpSampler.setMethod("GET");

        // Loop Controller
        LoopController loopController = new LoopController();
        loopController.setLoops(1);
        loopController.addTestElement(httpSampler);
        loopController.setFirst(true);
        loopController.initialize();

        // Thread Group
        ThreadGroup threadGroup = new ThreadGroup();
        threadGroup.setNumThreads(1);
        threadGroup.setRampUp(1);
        threadGroup.setSamplerController(loopController);

        // Test Plan
        TestPlan testPlan = new TestPlan("Create JMeter Script From Java Code");

        // Construct Test Plan from previously initialized elements
        testPlanTree.add("testPlan", testPlan);
        testPlanTree.add("loopController", loopController);
        testPlanTree.add("threadGroup", threadGroup);
        testPlanTree.add("httpSampler", httpSampler);

        // Run Test Plan
        jmeter.configure(testPlanTree);
        jmeter.run();

First of all, this code:

testPlanTree.add("testPlan", testPlan);
testPlanTree.add("loopController", loopController);
testPlanTree.add("threadGroup", threadGroup);
testPlanTree.add("httpSampler", httpSampler);

needs to be replaced by

testPlanTree.add(testPlan);
HashTree threadGroupHashTree = testPlanTree.add(testPlan, threadGroup);
threadGroupHashTree.add(httpSampler);

I also fail to see where you're saving the results into the .jtl, you need to add ResultCollector like this:

Summariser summer = null;
String summariserName = JMeterUtils.getPropDefault("summariser.name", "summary");
if (summariserName.length() > 0) {
    summer = new Summariser(summariserName);
}


String logFile = "/path/to/result.jtl";
ResultCollector logger = new ResultCollector(summer);
logger.setFilename(logFile);
testPlanTree.add(testPlanTree.getArray()[0], logger); 

before jmeter.configure(testPlanTree); line

In general creating JMeter tests using API is not very supported and there is no any guarantee that the code will work after next JMeter release so I would rather rely on 3rd-party options like Taurus or jmeter-java-dsl

However if for some reason you want to continue you can get some examples in Five Ways To Launch a JMeter Test without Using the JMeter GUI article and in jmeter-from-code repo