```ruby
# controller for the dashboard
class DashboardController < ApplicationController
  before_action :authenticate_user!

  def account
  end

  def billing
  end

  def inbox
    @conversations = current_user.conversations
  end

  def conversation
    conversation_id = params[:id]
    @conversation = Conversation.find(conversation_id)
  end
end
```

Add new message when rendering conversation
user
```ruby
# controller for the dashboard
class DashboardController < ApplicationController
  before_action :authenticate_user!

  def account
  end

  def billing
  end

  def inbox
    @conversations = current_user.conversations
  end

  def conversation
    conversation_id = params[:id]
    @conversation = Conversation.find(conversation_id)
    @message = Message.new(
      conversation: @conversation
    )
  end
end
```
assistant