You can publish your app by using the Publish / Update option in the menu screen. Or by touching on your App in the Apps lists, and touching the left panel publish / update / preview option. See pictures:
Only email verified users can publish. So check your inbox for activation mail(s). If you did not get them check you spam or junk folders. If you need to have you email address changed just contact us.
Looking to publish your App in the Google Play Store or Apple App store? Check this article