Configuring Tempo+OTeL for sending metrics

I am getting the following error, unable to figure out the root cause

2024/07/17 12:52:20 failed to upload metrics: failed to send metrics to http://tempo:4318/v1/metrics: 404 Not Found

I have been attempting to follow the dice demo as a way to learn how the LGTM stack. I am able to see spans in the Grafana dashboard, but in my service (running via Docker) I get the above error.

Below is the source code

LINK: github