Bots in production

I am trying to integrate Rasa chatbot to rest webapp . I am new to RASA. i have built a bot to trigger the rest call that will take some time to complete the response back .How can i handle such cases where response might take some time . There will be more than 20 users initially for the application . So how can i respond back to the user who initiated that rest call to a web application. Rasa bot can talk to nearly 5 different web applications and how can i present the response back