SwiftUI - Unable To Correctly Display JSON Data In App

I am having a bit of trouble trying to get data return from the MTA API (subway system in New York) (Link Here). The data is in GTFS, so I am using a parser that is set up in a virtual environment that converts the data to JSON and sends it to me (sample JSON posted later in post). Basically, the decoding of GTFS to JSON is completed.

Now that I have the JSON data, I need to get it to display in my app. I have dealt with APIs before, but not one with this many "layers".

The question is: how should I structure my code on the Swift side so I can access each of the datapoints sent in the JSON?

Below is what I am working. The data is not displaying at all in my ContentView. I am guessing this has to do with my model being structured incorrectly, therefore the data I am attempting to display not actually being there:

struct TrainResponse: Codable {
let data: [String]
let n, s: [NS]
let id: String
let lastUpdate: Date
let location: [Double]
let name: String
let routes: [String]
let stops: [String: [Double]]

enum CodingKeys: String, CodingKey {
    case data
    case n = "N"
    case s = "S"
    case id
    case lastUpdate = "last_update"
    case location, name, routes, stops
 }
}

// MARK: - N
struct NS: Codable {
let route: String
let time: Date
}


class API: ObservableObject {

@Published var storedData = String()
@Published var ns = NS.self
@Published var id = String()
@Published var lastUpdate = Date()
@Published var location = [Double]()
@Published var name = String()
@Published var routes = [String]()
@Published var stops = [String: [Double]]()

func loadData() {
    guard let url = URL(string: "http://127.0.0.1:5000/by-route/A") else {
        print("Your API end point is Invalid")
        return
    }
    let request = URLRequest(url: url)
    URLSession.shared.dataTask(with: request) { data, response, error in
        if let data = data {
            if let response = try? JSONDecoder().decode(TrainResponse.self, from: data) {
                DispatchQueue.main.async {
                    if let data = response.data.first {
                        self.storedData = data
                        
                        self.routes = response.routes
                        self.id = response.id
                        self.lastUpdate = response.lastUpdate
                        self.location = response.location
                        self.name = response.name
                        self.routes = response.routes
                        self.stops = response.stops
                    }
                }
                return
            }
        }
    }.resume()
  }
}

Below is a sample of the JSON - It repeats what you see below hundreds of times, but I closed it off in the sample as if it were a complete JSON object (to make it easier to debug)

{
"data": [
    {
        "N": [
            {
                "route": "A",
                "time": "2021-07-21T21:33:00-04:00"
            }
        ],
        "S": [
            {
                "route": "A",
                "time": "2021-07-21T21:34:40-04:00"
            }
        ],
        "id": "6d6a",
        "last_update": "2021-07-21T21:25:06-04:00",
        "location": [
            40.681711,
            -73.837683
        ],
        "name": "104 St",
        "routes": [
            "A"
        ],
        "stops": {
            "A63": [
                40.681711,
                -73.837683
            ]
        }
    }
    ],
    "updated": "2021-07-21T21:25:06-04:00"
}

I am really at wits end here. Any thoughts on how my code should be restructured to return the data correctly?

I know I should be nesting the data (e.g. self.routes = data["N"].etc.etc but I can't quite seem to figure out how to structure my code so I can do that. Once that is done, I should have no trouble displaying the data in the app.. just need to get the data into the app first!

EDIT - Adding code for contentview

import SwiftUI

struct ContentView: View {

@StateObject var api = API()

var body: some View {
    Text("yo")
    
    List {
        ForEach(api.routes, id: \.self) { index in
            Text(index)
        }
    }
    .onAppear { api.loadData() }
    
  }
}

EDIT 2 I have updated the data models. They now look like the following:

    struct Main: Codable {
    let data: [Datum]
    let updated: String
}

// MARK: - Datum
struct Datum: Codable {
    let n, s: [N]
    let id: String
    let lastUpdate: Date
    let location: [Double]
    let name: String
    let routes: [String]
    let stops: [String: [Double]]

    enum CodingKeys: String, CodingKey {
        case n = "N"
        case s = "S"
        case id
        case lastUpdate = "last_update"
        case location, name, routes, stops
    }
}

// MARK: - N
struct N: Codable {
    let route: String
    let time: Date
}