In your Swift app, ask the user for permission, register with APNs, then convert the returned Data into the lowercase hex string edgepush expects.

// AppDelegate.swift
import UIKit
import UserNotifications

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

  func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    UNUserNotificationCenter.current().requestAuthorization(
      options: [.alert, .sound, .badge]
    ) { granted, _ in
      guard granted else { return }
      DispatchQueue.main.async {
        application.registerForRemoteNotifications()
      }
    }
    return true
  }

  func application(
    _ application: UIApplication,
    didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data
  ) {
    // edgepush expects 64 lowercase hex characters
    let token = deviceToken.map { String(format: "%02x", $0) }.joined()
    Task { await registerToken(token) }
  }

  func application(
    _ application: UIApplication,
    didFailToRegisterForRemoteNotificationsWithError error: Error
  ) {
    print("APNs registration failed:", error)
  }
}