Generic struct "WindowGroup" requires that "ViewController confirm to "View" - swift

Question

I'm trying to build a simple Pomodoro timer and Swift is complaining with two errors:
Generic struct 'WindowGroup' requires that 'ViewController' conform to 'View'
Static method 'buildBlock' requires that 'ViewController' conform to 'View'
ContentView.swift
import UIKit
class ViewController: UIViewController {
// MARK: - Properties
let pomodoroDuration = 25 * 60 // 25 minutes
var timer = Timer()
var remainingSeconds = 0
// MARK: - Outlets
#IBOutlet weak var timeLabel: UILabel!
#IBOutlet weak var startButton: UIButton!
#IBOutlet weak var stopButton: UIButton!
// MARK: - View Life Cycle
override func viewDidLoad() {
super.viewDidLoad()
stopButton.isEnabled = false
}
// MARK: - Actions
#IBAction func startTimer(_ sender: Any) {
remainingSeconds = pomodoroDuration
startButton.isEnabled = false
stopButton.isEnabled = true
timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { [weak self] timer in
guard let self = self else { return }
if self.remainingSeconds > 0 {
self.remainingSeconds -= 1
self.updateTimeLabel()
} else {
timer.invalidate()
self.resetTimer()
// Add code to track completed pomodoros here
}
}
}
#IBAction func stopTimer(_ sender: Any) {
timer.invalidate()
resetTimer()
}
// MARK: - Helper Methods
func updateTimeLabel() {
let minutes = remainingSeconds / 60
let seconds = remainingSeconds % 60
timeLabel.text = String(format: "%02d:%02d", minutes, seconds)
}
func resetTimer() {
startButton.isEnabled = true
stopButton.isEnabled = false
timeLabel.text = "25:00"
}
}
The build error show in below file
TomatoApp.swift
import SwiftUI
#main
struct TomatoApp: App {
var body: some Scene {
WindowGroup {
ViewController()
}
}
}