Each Organization using email to sign in has a unique Access Code assigned to them. This Access Code is used only when a user is first creating their account in the Shine app.
This Access Code ensures the privacy of your "walled garden" and that only your members can login to your Shine Organization.
If you sign up through the Dashboard (online), you created an app user for yourself, and will therefore not need to use your Organization's Access Code when signing into the app. Instead, and as each other user will do after their initial login, you will select "Login as Existing User" and input the email and password you used in the Dashboard. You should still look up your Access Code in the Dashboard so you can help other users login.
I logged in with Slack/Yammer: Good news, you can disregard this article because Organizations that use Slack or Yammer for Authentication do not require an Access Code.