Add IDP integrations for self-hosted Netbird

docs/integrations/identity-providers/self-hosted/auth0.md

@@ -0,0 +1,41 @@
+---
+id: using-netbird-with-auth0
+title: Using NetBird with Auth0
+sidebar_position: 1
+tags:
+- integrations
+- idp
+- auth0
+- oidc
+- how-to
+---
+
+This guide is a part of the [NetBird Self-hosting Guide](/getting-started/self-hosting) and explains how to integrate **self-hosted** NetBird with [Auth0](https://auth0.com/).
+
+Auth0 is a flexible, drop-in solution to add authentication and authorization services to your applications. 
+It is a 3rd party managed service and can't be self-hosted. Auth0 is the right choice if you don't want to manage an Identity Provider (IDP) 
+instance on your own. 
+
+:::tip self-hosted idp
+If you prefer to have full control over authentication and authorization of your NetBird network, there are good
+self-hosted alternatives to the managed Auth0 service like [Keycloak](/integrations/identity-providers/self-hosted/using-netbird-with-keycloak).
+:::
+
+### Step 1: Create Auth0 account
+To create an Auth0 account, sign up at [https://auth0.com](https://auth0.com/).
+
+### Step 2: Configure Auth0 properties in the setup.env file
+1. Configure ```NETBIRD_AUTH0_DOMAIN``` and ```NETBIRD_AUTH0_CLIENT_ID``` properties.
+
+    * To obtain these, please use [Auth0 React SDK Guide](https://auth0.com/docs/quickstart/spa/react/01-login#configure-auth0) up until "Install the Auth0 React SDK".
+
+      > Use ```https://YOUR DOMAIN``` as ````Allowed Callback URLs````, ```Allowed Logout URLs```, ```Allowed Web Origins``` and ```Allowed Origins (CORS)```
+    * set the variables in the ```setup.env```
+    * :warning: Make sure that `Token Endpoint Authentication Method` is set to `None` in your Auth0 Default Application
+2. Configure ```NETBIRD_AUTH0_AUDIENCE``` property.
+
+    * Check [Auth0 Create An API](https://auth0.com/docs/quickstart/backend/golang#create-an-api) section to obtain AuthAudience.
+    * set the property in the ```setup.env``` file.
+
+### Step 3: Continue with the self-hosting guide
+You can now continue with the [NetBird Self-hosting Guide](/getting-started/self-hosting).