An example how to trigger animations with SwiftUI

ContentView.swift

import SwiftUI

struct ContentView: View {
    @StateObject private var state: ContentViewState = .init()
    
    var body: some View {
        ZStack {
            VStack {
                Text(state.count.description)
                Button("Count Up") {
                    state.countUp()
                }
                Button("Flash") {
                    state.shouldFlash = true
                }
            }
            FlashView(shouldFlash: $state.shouldFlash)
                .ignoresSafeArea()
                .allowsHitTesting(false)
        }
    }
}

final class ContentViewState: ObservableObject {
    @Published var shouldFlash: Bool = false
    @Published private(set) var count: Int = 0
    
    func countUp() {
        count += 1
    }
}

struct FlashView: UIViewRepresentable {
    @Binding var shouldFlash: Bool
    
    func makeUIView(context: Context) -> UIView {
        let view = UIView()
        view.backgroundColor = .red
        view.alpha = 0.0
        if shouldFlash {
            makeViewFlash(view)
        }
        return view
    }
    
    func updateUIView(_ view: UIView, context: Context) {
        if shouldFlash {
            makeViewFlash(view)
        }
    }
    
    private func makeViewFlash(_ view: UIView) {
        view.alpha = 1.0
        UIView.animate(withDuration: 0.2, delay: 0.0, options: .curveEaseOut, animations: {
            view.alpha = 0.0
        })
        shouldFlash = false
    }
}