You gotta get 5000 points or more and donate it, then you get a password from your Tamagotchi. You put the password into the password window when you click on the King in Tama Town, and he'll give you a password for your Tamagotchi. It's a ring. I'd give you my password but they only work for specific usernames. Sorry
You need to donate at least three seperate times to get the password. Try donating a few more points. Then do it again and you should have the password.