FCM - Cannot find type 'MessagingRemoteMessage' in scope

This is the code I use in my AppDelegate in order to receive messages in iOS:

extension AppDelegate : MessagingDelegate {
  // [START refresh_token]
  func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String?) {
    print("Firebase registration token: \(fcmToken)")
    
    let dataDict:[String: String?] = ["token": fcmToken]
    NotificationCenter.default.post(name: Notification.Name("FCMToken"), object: nil, userInfo: dataDict)
    // Note: This callback is fired at each app startup and whenever a new token is generated.
  }

  func messaging(_ messaging: Messaging, didReceive remoteMessage: MessagingRemoteMessage) {
    print("Received data message: \(remoteMessage.appData)")
  }
}

I have recently started getting this error message after compiling:

Cannot find type 'MessagingRemoteMessage' in scope

which makes the build fail.

What should I do in order to fix this?