How can I get tanki test server code?
The test servers are only open for mass testing when a huge player base is needed to test an update. Though otherwise testing is help privately only for Testers to take part in, this is why you were prompted to give an invite code, as only official Testers have it. To apply you must speak fluent Russian among other things, and may fill out the application here: Application.
Сервис поддержки клиентов работает на платформе UserEcho