A single page app, implemented with an ASP.NET Web API backend, that signs up & signs in users using Azure AD B2C and calls the web API using OAuth 2.0 access tokens.
There's a newer version of this sample taking advantage of the Microsoft Authentication Library for JavaScript.
Check it out here: active-directory-b2c-javascript-msal-singlepageapp
If you really need a sample that uses the hello.js library for B2C authentication, you can navigate to the master branch, but please know that it's no longer supported.