Swift - Unable to open a realm at path, open() failed: Operation not permitted

I have created a realm database, and I can fetch the data on my iOS application class on the mobile device. but I need to fetch data from the custom keyboard extension class of the same application. I got a realm. lock file operation not permitted error is thrown as

CustomKey/KeyboardViewController.swift:630: Fatal error: ‘try!’ expression unexpectedly raised an error: Error Domain=io.realm Code=3 “Failed to open file at path ‘/private/var/mobile/Containers/Shared/AppGroup/23DD1FD4-A291-4599-9D5F-84057FE6CF26/BigramFileShared.realm.lock’: Operation not permitted” UserInfo={Error Code=3, NSFilePath=/private/var/mobile/Containers/Shared/AppGroup/23DD1FD4-A291-4599-9D5F-84057FE6CF26/BigramFileShared.realm.lock, Error Name=PermissionDenied, NSLocalizedDescription=Failed to open file at path '/private/var/mobile/Containers/Shared/AppGroup/23DD1FD4-A291-4599-9D5F-84057FE6CF26/BigramFileShared.realm.lock**': Operation not permitted**

I tried the input source:

      let strpath = userDefaultAddress?.value(forKey: "shared_bigram_file_path")
        let realmURL = URL(fileURLWithPath: strpath as! String )
        let config = Realm.Configuration(fileURL: realmURL)
        let realm = try! Realm()
        // Get our Realm file's parent directory
       // let folderPath: ()? =  Realm.Configuration.defaultConfiguration.fileURL?.deleteLastPathComponent()
        let folderPath = realm.configuration.fileURL!.deletingLastPathComponent().path

        // Disable file protection for this directory
        try! FileManager.default.setAttributes([FileAttributeKey(rawValue: FileAttributeKey.protectionKey.rawValue): FileProtectionType.none], ofItemAtPath: folderPath)
        do {
            let realm = try Realm(configuration: config)
            let results = realm.objects(IndianSpace.self)
        } catch {
            print("Error opening Realm: \(error)")