Ask HN: White Labeled SSO for Developed Apps

I'm looking for a white labeled SSO experience that I can use for applications that I develop. Creating user management screens is a waste of time. I know there are cloud IAM systems. But I'm not sure if any provide a white labeled experience for all aspects of user management. User creation, organization hierarchy, organization admin creation, user self management, optional 2-factor setup, etc. With a clean API for quick integration into any apps I build. I mainly want to do zero UI work for all things user creation and management related. I hate building auth screens and user management screens every time I build a new app, and I want the SSO experience. White labeling is not a requirement, but would be nice. Any services you've used?