You use the functionality you have to have provided a valid email address when you signed up. If you didn't, you should contact gatari helpdesk in vk from the attached account (to prove your identity). If you didn't attach your vk either, you can try contacting Firedigger in discord or twitch, obviously only from attached account. If you didn't attach anything and have an invalid email address, you have low chances of restoring the account, in that case you should contact gatari helpdesk in vk for the instructions. It is a good idea to at least provide the key you used for reg in that case.