To authorize your requests, the support sometimes requires you to provide a PIN: it is a 4 digits generated for your account. NIC.UA support may request it to confirm the order of service, transfer of hosting between accounts and other operations.
You can find the pin code for support in your personal cabinet, in the "dashboard" section:
To get the PIN, click on the "Show" button. There you will also be able to generate a new code, if required. It is not possible to set the PIN yourself.