Help with Widget Configuration

Hello, I'm working on my first app. It's also my first encounter with App Intents.

I have a data structure for events that has an ID (String), a name (String), a Date and an image (Data). The user can create them in the app and they are stored with CoreData.

I wanted to have a widget that would allow the user to choose from their list of events and display that event in the widget. The list should appear in the widget configuration and it would be a list of the names and (if possible) the image.

I think I have found how to access the information from the widget, but I cannot figure out how to have the list appear in the configuration. I have been following this guide: https://developer.apple.com/documentation/widgetkit/making-a-configurable-widget?utm_source=pocket_saves. But that one shows hardcoded elements in the list and I haven't been able to find how to have the list change in relation to the content of the app.

This is what I have made so far in the AppIntent file:

import WidgetKit
import AppIntents
import CoreData

struct EventDetail: AppEntity {
    static var defaultQuery: EventQuery = EventQuery()

    var id: String
    var date: Date
    var image: Data
    var title: String

    static var typeDisplayRepresentation: TypeDisplayRepresentation = "Event"

    var displayRepresentation: DisplayRepresentation {
        DisplayRepresentation(title: "\(id) \(title)")
    }
}

struct EventQuery: EntityQuery{
    func entities(for identifiers: [EventDetail.ID]) async throws -> [EventDetail] {
        return fill_event_details(events_list: getEventDataIntent())
    }

    func suggestedEntities() async throws -> [EventDetail] {
        fill_event_details(events_list: getEventDataIntent()).filter { $0.id != "-" }
    }

    func defaultResult() async -> EventDetail? {
        try? await suggestedEntities().first
    }
}

struct ConfigurationAppIntent: WidgetConfigurationIntent {
    static var title: LocalizedStringResource = "Select an event"
    static var description = IntentDescription("This is an example widget.")

    // An example configurable parameter.
    @Parameter(title: "Event")
    var event: EventDetail


//    init(events: [UserCountdowns]) {
//        self.event = fill_event_details(events_list: events)[0]
//        print("AppIntent")
//        print(self.event.title)
//    }


    init() {
    }
}

func fill_event_details(events_list: [UserCountdowns]) -> [EventDetail] {
    var entities_list: [EventDetail]?

    let events = getEventDataIntent()

    for event in events {
        entities_list!.append(EventDetail(id: event.id!, date: event.date!, image: event.image!, title: event.title!))
    }

    return entities_list ?? [EventDetail(id: "-", date: Date(), image: Data(), title: "empty")]
}

func getEventDataIntent() -> [UserCountdowns] {
    let context = PersistenceController.shared.container.viewContext

    let request = UserCountdowns.fetchRequest()

    var result: [UserCountdowns]!

    do {
        result = try context.fetch(request)
    }
    catch {
        print(error)
    }

    return result
}

I have been trying a few things in the widget's code but I haven't been able to make anything work, so I don't really have anything worth sharing, I think.

This is the code for the UserCountdowns structure:

extension UserCountdowns {

    @nonobjc public class func fetchRequest() -> NSFetchRequest<UserCountdowns> {
        return NSFetchRequest<UserCountdowns>(entityName: "UserCountdowns")
    }

    @NSManaged public var date: Date?
    @NSManaged public var image: Data?
    @NSManaged public var title: String?
    @NSManaged public var id: String?

}

Could anyone help me with this, please? What am I missing or what would the next step be?

Let me know if there is any other part of the code I should share.

Thank you in advance!