How to make a chatbot deployed on a VM accesible from http in my website?

I created a chatbot with RASA Open Source and deployed it on a GCP VM (Ubuntu 18.04) by following this tutorial Deploy a Rasa Chatbot on a Virtual Machine on Google Cloud Platform (GCP). When I use that URL with my website’s widget, I can communicate with my chatbot IF the website is operating locally (localhost), but it does not work when deployed to Vercel or Netlify.

I used ngrok to construct a tunnel to port 5005, and then used the ngrok https URL as the app’s endpoint to communicate with the chatbot. So, my issue is, how can I have my website communicate with the VM via http or https without using ngrok?

Thank You Very Much.