Generate a device token for iOS

• An Xcode project with a valid Apple Developer account.
• A physical iOS device (the iOS simulator does not support push notifications).
• The Push Notifications capability enabled in your Xcode project (select your target, go to Signing & Capabilities, and click + Capability to add Push Notifications).

Before registering for remote notifications, request the user's permission to display alerts, sounds, and badges. Call requestAuthorization on UNUserNotificationCenter and, if the user grants permission, register for remote notifications.

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import UserNotifications
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func requestNotificationPermission() {
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    UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound, .badge]) { granted, error in
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        if let error = error {
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            print("Error requesting notification permission: \(error)")
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            return
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        }
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        if granted {
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            DispatchQueue.main.async {
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                UIApplication.shared.registerForRemoteNotifications()
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            }
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        }
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    }
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}

Call this method early in your app's lifecycle, such as in application(_:didFinishLaunchingWithOptions:).

After you call registerForRemoteNotifications(), the system contacts APNs and returns a device token through the AppDelegate. Implement the following delegate methods to handle the result.

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func application(_ application: UIApplication,
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                 didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
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    let token = deviceToken.map { String(format: "%02.2hhx", $0) }.joined()
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    // Send this token to Twilio using the DeviceRegistrations API
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    // or include it directly in a PushNotifications request.
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}
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func application(_ application: UIApplication,
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                 didFailToRegisterForRemoteNotificationsWithError error: Error) {
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    print("Failed to register for remote notifications: \(error)")
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}

The deviceToken is returned as raw Data. The code above converts it to a hexadecimal string, which is the format Twilio expects in the token field.

APNs device tokens can change over time. iOS calls application(_:didRegisterForRemoteNotificationsWithDeviceToken:) each time the token is updated, including on every app launch. Always send the latest token to your server to ensure Twilio can continue delivering notifications.

After you retrieve the token, include it in Twilio Push Notifications API requests using "provider": "APN". You can either:

• Send directly: Include the token in the to array when sending a notification.
• Register the device: Store the token as a DeviceRegistration so you can send to Users by userId.

• Send a push notification using the token.
• Obtain APNs credentials to upload to Twilio.
• Review Apple's Registering your app with APNs guide for additional details.