View template files of Helm chart

you can use helm fetch if you want to download the whole chart:

download a chart from a repository and (optionally) unpack it in local directory

(from the doc)

helm inspect returns the default values.yaml for the chart:

This command inspects a chart and displays information. It takes a chart reference ('stable/drupal'), a full path to a directory or packaged chart, or a URL.

Inspect prints the contents of the Chart.yaml file and the values.yaml file.

(from the doc)

helm install yourchart --dry-run --debug

This will print to stdout all the rendered templates in the chart (and won't install the chart)