How to edit the Configurations of a Helm Chart?

You're trying to customize an installed chart. Please use this guide Customizing the Chart Before Installing.

The key parts:

There are two ways to pass configuration data during install:

• --values (or -f): Specify a YAML file with overrides. This can be specified multiple times and the rightmost file will take precedence
• --set name=value: Specify overrides on the command line

I guess helm upgrade is that are you looking for.

This command upgrades a release to a specified version of a chart and/or updates chart values.

So if you have deployed prometheus-adapter, you can use command helm fetch

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

You will have all yamls, you can edit them and upgrade your current deployed chart via helm upgrade

I found an example, which should explain it to you more precisely.