Can't get iCloud root directory on iCould Documents

I couldn't get iCloud root directory ("iCloud Drive not available or user domain not found."). Anybody had similar issue? I don't want to CloudKit.

Xcode: Version 16.0 I have done below:

• Settings > iCloud Backup ON
• Settings > iCloud > iCloud Drive ON
• Settings > iCloud > MyApp ON

import Foundation
import UIKit

class BackupManager {
    
    var isiCloudEnabled: Bool {
        (FileManager.default.ubiquityIdentityToken != nil)
    }

    // Get the iCloud Drive folder and create a folder if needed
    func createFolder() -> URL? {
        let fileManager = FileManager.default
        
        // Access the iCloud Drive root directory (user-visible folder)
        guard let iCloudRootURL = fileManager.url(forUbiquityContainerIdentifier: nil)?
            .appendingPathComponent("Documents") else {
            print("iCloud Drive not available or user domain not found.")
            return nil
        }

        // Check if the folder exists in iCloud Drive root, if not, create it
        if !fileManager.fileExists(atPath: iCloudRootURL.path) {
            do {
                try fileManager.createDirectory(at: iCloudRootURL, withIntermediateDirectories: true, attributes: nil)
                print("Folder created in iCloud Drive")
            } catch {
                print("Error creating folder: \(error.localizedDescription)")
                return nil
            }
        }
        
        // Return the URL of the folder in iCloud Drive
        return iCloudRootURL
    }

}