Ludwig's answer is correct. As additional help, I'll quote you Rules 3 & 7 from our game rules:
3. Account sharing
Players must keep their own login data, passwords and access data secret. Disclosing your password to other players is strictly prohibited.
As a player, you can only play your own account. Accessing another player’s account is strictly prohibited.
Make sure to choose a secure password and remember it is your responsibility to keep it secret. Please inform us promptly if third parties gain unauthorized access to your account.
If someone gives you their own password, please report them.
7. Pushing
Operating a “push-account” is forbidden. This is defined as unbalanced routine resource (resources, Knowledge Points etc.) transfers from one account to the next even if involved accounts do not belong to the same player.
It is forbidden to create trades in any form (goods, Knowledge Points etc.) that involve multiple worlds.
Please note that it is strictly forbidden to use the invite feature to invite yourself or players that share an internet connection with you.