SwiftData: Failed to find any currently loaded container for Todo)

I have no idea why I'm getting this error. Here is my code for the App, the page where I think the problem is occurring, and my class:

App File:

@main
struct To_DoApp: App {
    var body: some Scene {
        WindowGroup {
            ContentView()
                .environment(IconNames())
        }
        .modelContainer(for: Todo.self)
    }
}

@Observable
class IconNames {
    var iconNames: [String?] = [nil]
    var currentIndex = 0
    
    init() {
        getAlternateIconNames()
        
        if let currentIcon = UIApplication.shared.alternateIconName {
            self.currentIndex = iconNames.firstIndex(of: currentIcon) ?? 0
        }
    }
    
    func getAlternateIconNames() {
        if let icons = Bundle.main.object(forInfoDictionaryKey: "CFBundleIcons") as? [String: Any],
            let alternateIcons = icons["CFBundleAlternateIcons"] as? [String: Any] {
            for (_, value) in alternateIcons {
                guard let iconList = value as? Dictionary<String, Any> else { return }
                guard let iconFiles = iconList["CFBundleIconFiles"] as? [String] else { return }
                guard let icon = iconFiles.first else { return }
                
                iconNames.append(icon)
            }
        }
    }
}

My class:

@Model
class Todo {
    var name: String
    var details: String
    var priority: String
    var date: Date
    
    init(name: String = "", details: String = "", priority: String = "Normal", date: Date = .now) {
        self.name = name
        self.details = details
        self.priority = priority
        self.date = date
    }
}

And the page where I think the error is occurring:

struct AddTodoView: View {
    @Environment(\.modelContext) var modelContext
    @Environment(\.dismiss) var dismiss
    
    @State private var name = ""
    @State private var details = ""
    @State private var priority = "Normal"
    @State private var date = Date.now
    
    let priorities = ["High", "Normal", "Low"]
    
    @State private var errorShowing: Bool = false
    @State private var errorTitle: String = ""
    @State private var errorMessage: String = ""
    
    var theme = ThemeSettings()
    var themes: [Theme] = themeData
    
    
    var body: some View {
        NavigationStack {
            VStack {
                VStack(alignment: .leading, spacing: 20) {
                    TextField("Todo", text: $name)
                        .padding()
                        .background(Color(UIColor.tertiarySystemFill))
                        .cornerRadius(9)
                        .font(.system(size: 24, weight: .bold, design: .default))
                    
                    TextField("Details", text: $details, axis: .vertical)
                        .padding()
                        .background(Color(UIColor.tertiarySystemFill))
                        .cornerRadius(9)
                    
                    Picker("Priority", selection: $priority) {
                        ForEach(priorities, id: \.self) {
                            Text($0)
                        }
                    }
                    .pickerStyle(.segmented)
                    
                    DatePicker("Date", selection: $date)
                    
                    Button {
                        if name != "" || details != "" {
                            let todo = Todo()
                            todo.name = name
                            todo.details = details
                            todo.priority = priority
                            todo.date = date
                            
                            do {
                                try modelContext.save()
                                dismiss()
                            } catch {
                                print(error.localizedDescription)
                            }
                        } else {
                            errorShowing = true
                            errorTitle = "Invalid Name"
                            errorMessage = "Make sure to enter something for\nthe new todo item."
                            return
                        }
                    } label: {
                        Text("Save")
                            .font(.system(size: 24, weight: .bold, design: .default))
                            .padding()
                            .frame(minWidth: 0, maxWidth: .infinity)
                            .background(themes[theme.themeSettings].themeColor)
                            .cornerRadius(9)
                            .foregroundStyle(.white)
                    }
                }
                .padding(.horizontal)
                .padding(.vertical, 30)
                
                Spacer()
            }
            .navigationTitle("New Todo")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                Button {
                    dismiss()
                } label: {
                    Image(systemName: "xmark")
                }
            }
            .alert(errorTitle, isPresented: $errorShowing) { }
            message: {
                Text(errorMessage)
            }
        }
        .tint(themes[theme.themeSettings].themeColor)
    }
}