Adding Login Items for macOS

sample.swift

func applicationDidFinishLaunching(_ aNotification: Notification) {
    let runningApps = NSWorkspace.shared.runningApplications
    let isRunning = runningApps.contains {
        $0.bundleIdentifier == "your.domain.TestAutoLaunch"
    }

    if !isRunning {
        var path = Bundle.main.bundlePath as NSString
        for _ in 1...4 {
            path = path.deletingLastPathComponent as NSString
        }
        NSWorkspace.shared.launchApplication(path as String)
    }
}

sampleVC.swift

import Cocoa
import ServiceManagement

class ViewController: NSViewController {
    
    let helperBundleName = "your.domain.AutoLaunchHelper"

    @IBOutlet weak var autoLaunchCheckbox: NSButton!
    
    @IBAction func toggleAutoLaunch(_ sender: NSButton) {
        let isAuto = sender.state == .on
        SMLoginItemSetEnabled(helperBundleName as CFString, isAuto)
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()

        let foundHelper = NSWorkspace.shared.runningApplications.contains {
            $0.bundleIdentifier == helperBundleName
        }
        
        autoLaunchCheckbox.state = foundHelper ? .on : .off
    }
}