Trailing closure passed to parameter of type 'Int' that does not accept a closure

Which line exactly ? Is it line 3 or 4 ? If so, please show how onboardingData and OnboardingCard are defined. Otherwise tell exactly where you get the error.

1.    VStack {
2.     TabView {
3.       ForEach(onboardingData) { onboardingItem in
4.          OnboardingCard(onboardingItem: onboardingItem)
5.       }
6.   }
7.   .tabViewStyle(PageTabViewStyle(indexDisplayMode: .automatic))
8.   .indexViewStyle(PageIndexViewStyle (backgroundDisplayMode: .always))
9.   .foregroundColor(.white)
10. }

on line 2 I get error, in TabView , and  how onboardingData and OnboardingCard are defined it is defined as

OnboardingCard:

fileprivate struct OnboardingCard: View {
  let onboardingItem: OnboardingItem
    var body: some View {
      VStack {
        Image(onboardingItem.imageName)
         .resizable()
        .frame(width:340, height:340)
       
        Text(onboardingItem.title)
        .font(.title)
          .foregroundColor(.black)
        .bold()
        .padding()
        Text(onboardingItem.description)
        .multilineTextAlignment(.center)
        .font(.body)
        .foregroundColor(.gray)
        .padding (.horizontal, 15)
        }
       }
       }

onboardingData:

  var onboardingData: [OnboardingItem] = [
  OnboardingItem(imageName: "image1", title: "Welcome1", description: "description1"),
  OnboardingItem(imageName: "image2", title: "Welcome2", description: "description2"),
    OnboardingItem(imageName: "image3", title: "Welcome3", description: "description3"),
  OnboardingItem(imageName: "image4", title: "Welcome4", description: "description4")
  ]

Doc states :

Tab views only support tab items of type Text, Image, or an image followed by text. Passing any other type of view results in a visible but empty tab item.

like in

TabView {
    Text("The First Tab")
        .badge(10)
        .tabItem {
            Image(systemName: "1.square.fill")
            Text("First")
        }

That's not the case with your code: you return OnboardingCard

ForEach(onboardingData) { onboardingItem in 
    OnboardingCard(onboardingItem: onboardingItem)
}

What is the purpose of VStack for TabView ?

As OOPers and Claude mentions in comment, when we called the TabView as MyTabView problem solved