The first time you use a github-organization for iterapp, you need to connect the two.
Register this app on your github-organization: https://github.com/apps/headless-operations. If you choose to just install the app for a subset of repos, they will be the only one you will be able to deploy.
You can use
/iterapp as for an interal app, except that you always need to use
the full name of the app (i.e
yourorg/yourapp) and that you will get a domain
on iterapp.no instead of app.iterate.no/test.iterate.no