# config/initializers/avo.rb
Avo.configure do |config|
  config.authenticate_with do
    authenticate_admin_user
  end
end
```

Note that Avo's `ApplicationController` does not inherit from your app's `ApplicationController`, so any protected methods you defined would not work. Instead, you would need to explicitly write the authentication logic in the block. For example, if you store your `user_id` in the session hash, then you can do:

```ruby