Update auth0.md

Added more detail to the section on working alongside a User model

Author: Driptap

docs/guides/authentication/auth0.md

@@ -1,7 +1,7 @@
 ---
 description: Integrating with Auth0.
 sidebar_position: 6
-sidebar_label: 🚧 Auth0
+sidebar_label: Auth0
 ---
 
 # Integrating With Auth0
@@ -97,7 +97,7 @@ const currentUser = async (req) => {
 
   return {
     id: session.user.sub,
-    dbUserExists: !isNull(dbUser),    // Cause onboarding behavior 
+    dbUserExists: !isNull(dbUser),    // If the user doesn't exist in the database, this variable can be set in the session
   };
 };
 
@@ -108,6 +108,45 @@ export const getPrisma = async (req) => {
 };
 ```
 
+You can use the result of this token to redirect a user to an onboarding flow, such as a signup form:
+
+```ts
+app.get('/', async (req, res) => {
+  const user = await currentUser(req);
+  if (!user.dbUserExists) {
+    res.redirect('/onboarding');
+  }
+  res.send('hello user');
+});
+```
+
+and create a user record using the ID from the Auth0 session, here's a small example using the Auth0 React SDK:
+
+```ts
+import React from "react";
+import { useAuth0 } from "@auth0/auth0-react";
+
+const Profile = () => {
+  const { user, isAuthenticated, isLoading } = useAuth0();
+  const { trigger, isMutating } = useCreateUser();
+
+  const createUser = useCallback(async (event: FormEvent<HTMLFormElement>) => {
+    const formData = new FormData(event.currentTarget);
+    const name = formData.get('name');
+
+    await trigger({
+      data: {
+        id: user.sub,
+        name: name,
+      },
+    });
+  }, [trigger, user])
+
+  return <UserForm onSubmit={createUser}/>
+};
+```
+
+
 When the client is created, the database is queried using the contents of the Auth0 token.
 
 In this case, the Auth type is what provide authentication, not the User model, for example: