ASP.NET OWIN quickstart -- /callback not found

I’m having some trouble with the ASP.NET (OWIN) quickstart project. The main one seems to be that /callback isn’t found when finishing the login/signup experience if I’m not using the Lock UI for my universal login experience. I’m not sure where to begin in troubleshooting here, as I’m assuming that /callback URI is supposed to be provided by the OWIN middleware that is configured in Startup.cs, and I am unfamiliar with that.

The other thing of note is that the quickstart left in a placeholder in the web.config for auth0:Audience. It appears that this is supposed to map to the identifier of an API, but the only link on the quickstart guide documentation just takes me to the dashboard with no further guidance. I have created an API and added the identifier in this place, but access is denied and I’m not sure what further steps are necessary to link the application and the API.

I mention this, because to get the project running (and apparently working as long as I use Lock instead of a custom login experience, even the default custom login), I did have to comment out the line in Startup.cs that used auth0:Audience, which is in a block related to OpenIdConnectRequestType.Authentication.

  1. Is my assumption that the removal of this line is why the custom login page fails correct? If so, where do I find information on what needs to be done to create an API that can be consumed by the quickstart and how do I set up permissions between the application used by the quickstart and the API?

  2. If that is not the cause of this issue, then why does the quickstart point back to /callback when /callback does not exist?