How to trigger a query after using the auth component to log in?

I just set up Custom Auth mode as described here. I followed the tutorial pretty much exactly, so I have a form step, an API call step, and a “define a variable” step where I define a TOKEN to be used in all subsequent calls to my API. This works as expected.

However, I’d like to trigger a query after a user attempts to log in. For instance, I’d like to set the value of an error message if the login attempt failed, trigger an API call to check if the user is an admin after a successful login attempt, and set some environment variables to toggle the hidden status of components.

I don’t see any way to trigger a query on success using the Auth component, the way there is for other components. Basically all you can do is rename or hide the modal button.

Any ideas for a way to trigger a query after the user successfully logs in? (Bonus if you know how to change the success message from Successfully authed! to something else, or suppress the default error message for a failed login!)