Enter your email address to which mail notification should be send. Then check the box inside the captcha box to confirm that you are a human being making the request.
Should you see the inscription Verification expired. check the box again inside the captcha box, do just that and check the captcha box again.
Click the Send button to submit your request, and should you receive a message saying Failed to verify that you are a human and not a robot, click the Refresh captcha link, and then check the captcha box. The captcha may present a box with images for you to confirm what you are seeing. This is it's way of verifying that indeed it is a human being making the request. Follow and do what is asks.