Your duolingo forum registration isn't automaticaly transferred to duome forum so in order to join duome forums you need to register with your existing or any other username and email; in any case it's advised that you choose a new password for the forum.
~ Duome Team
(Sorry, currently there are no native navajos yet, so this post is in english)
Yáʼátʼééh! You can add Navajo as your profile's flag, aoo´!