Action Details
Requirements and how-to articles for Steam's action:

You can enable Google Analytics for your Steam Store page and/or Community Hub for anonymised data about your traffic sources and visitor behaviour.

You need this to get it done:

Google Analytics Account
A Google Analytics account is required. Create one if you do not have one already.
Tracking ID
Create a new account and property in Analytics for your store page/community hub. You'll need to set the "Web Site URL" field above to be the URL of the page you will be using the tracking code for.
If you are tracking your store page, you will need to use this URL format:
If you are tracking your community hub, you will need to use this URL format:
Enabling Google Analytics in Steamworks
After creating a Tracking ID, see the official Steamworks documentation for the steps to enabling Google Analytics on your store page/community hub.
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How-To Articles
A list of useful links for you:

Steamworks Documentation - Google Analytics
Information about setting up Google Analytics for your store page and/or community hub.
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