the onion svc for altaddress.org is:

tp7mtouwvggdlm73vimqkuq7727a4ebrv4vf4cnk6lfg4fatxa6p2ryd.onion

The temp address generator and account registration forms are both broken on the onion service. Works on the clearnet service.

(edit) I should add that i have never seen the onion svc worked… perhaps it was always broken.