Metrics endpoint cannot be parsed using prom2json

I am attempting to compare the output of Couchbase Server 7.0s metrics endpoint to the output from our existing Go Exporter for the Couchbase Autonomous Operator, so we can develop a method for our customers to upgrade to using built in metrics.

I intended to use prom2json which is an official tool from Prometheus to parse the output of a metrics endpoint into json and then programmatically compare our output to server to identify gaps.

When executing this tool (using CURL output) i get the following error:

I've attached the CURL output, as you can either pipe in the data from curl, or you can use prom2json on a specific file or url.

When i execute the tool against the prom-7.prom output i get the following empty array:

I've also attached the exporter's output when I use prom2json on it's metrics endpoint.