That depends on why the validation process was not successful. In the e-mail informing you about the outcome of the validation process, you will usually find information instructing you what to do next. If this information doesn’t help, please contact hvv switch customer service. If you meet the requirements for a successful validation, you can try again using the app or by visiting the service point that is processing your validation. You will need a stable Wi-Fi connection and a device with a camera and microphone to be able to make use of the video identification procedure in the app.