Rails Hello World Returning Backend 404

Following this tutorial, Demo: Deploy to GKE from GitLab - YouTube,

I have mapped my ingress endpoint to http://mudah.amiyn.com. Whether using the ingress IP, or my domain URL,, the 404 returns. I am fairly new to Gitlab, Kubernetes, and GKE, so I am not sure what all will be helpful to provide. Please advise.

The project I forked for this is : auto-devops-examples / minimal-rails-app · GitLab
After that, I followed everything verbatim from the tutorial.