Setting up Auth0 account
Before you start you need Auth0 account. If you don't have one, go to https://auth0.com/signup and sign up. There is a Free pricing plan.
Moreover, you can participate in the Open Source Program (if you qualified) and get all the features for free.
Auth0 is an Identity-as-a-Service (IDaaS) provider. Auth0 provides customers with a Universal Identity Platform for their web, mobile, IoT, and internal applications.