SuperTokens is an open source authentication solution offering features like: Different types of login: Email / password, Passwordless (OTP or Magic link based).

SuperTokens.com

Hello! I am new here and a bit lost. Does the kubernetes image w/postgres come with an Admin UI? Or how am I supposed to manage self-hosted SuperTokens?

The admin ui is provided by our backend SDK

You should start by following one of our guides: https://supertokens.com/docs/guides

Or you can use our CLI to start as well: npx create-supertokens-app@latest

Thanks. I think I now get it. The API is provided by supertokens core, and the UI layer is provided by the library

the core provides the API which the backend SDK queries. 

The backend SDK integrates with your app's API layer and exposes auth APIs via a middlware

The frontend SDK queries the APIs exposed by the backend SDK