I can't understand why posts are not loading in firebase - swift

Question

firebase does not write, although it seems to be syntactically correct. The application compiles, but no writes take place.
The documentation also seems to be correct.
the logic is simple. The user uploads a file from the phone, the file is sent to the repository
#IBAction func addButtonTouchUpInside(_ sender: Any) {
ProgressHUD.show("Waiting...", interaction: false)
if let profileImg = self.selectedImage, let imageData = image?.jpegData(compressionQuality: 0.4){
let photoIdString = NSUUID().uuidString
let storageRef = Storage.storage().reference(forURL: https://example.com).child("posts").child(photoIdString)
storageRef.putData(imageData, metadata: nil, completion: {(metadata, error) in
if error != nil {
ProgressHUD.showError(error!.localizedDescription)
return
}
let photoUrl = storageRef.downloadURL(completion: {url, error in
if error != nil {
print("Failed to download url:", error!)
return
} else {
let url = url?.absoluteString
self.sendDataToDatabase(photoUrl: url!)
}
})
})
}
}
func sendDataToDatabase(photoUrl: String){
let ref = Database.database().reference()
let postsReference = ref.child("posts")
let newPostId = postsReference.childByAutoId().key
let newPostReference = postsReference.child(newPostId!)
newPostReference.setValue(["photoUrl": photoUrl], withCompletionBlock: {
(Error, ref) in
if Error != nil {
ProgressHUD.showError(Error!.localizedDescription)
return
}
ProgressHUD.showSuccess("Success")
})
}
}
extension PerformViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate{
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]){
print("Did finish picking media")
if let image = info[UIImagePickerController.InfoKey.originalImage ] as? UIImage{
selectedImage = image
photo.image = image
}
dismiss(animated: true, completion: nil)
}
}