I have not received the registration confirmation e-mail.

Clappit sends the confirmation e-mail registration completed the purchase process.
Check to see if your e-mail did not end up in your spam or spam folder and you typed the correct e-mail address. As an example, here are some common mistakes. Entering a wrong domain (gmail.IT instead of gmail.COM), typos (lucarossi @ ... instead of luca.rossi @ ...). In case of further difficulties, try also to close the navigation window, delete the history and any cookies, reopen the browser and repeat the process.