Install-Package Nabbix

// Class containing a single Zabbix Item 'long_example'
private class MyCounter
{
	private long _incrementing;
    internal void Increment()
	{
		Interlocked.Increment(ref _incrementing);
	}

	[NabbixItem("long_example")]
    public long Incrementing => Interlocked.Read(ref _incrementing);
}

private static void Main()
{
	// Create the instance of the counter class with a single Zabbix Item
    var counters = new MyCounter();
            
    // Start the agent.
    var agent = new NabbixAgent(10052, counters);

    // Increment the counter. Normally done on API or method call.
    counters.Increment();

    // Shutdown
	Console.ReadKey();
    agent.Stop();
}