Install the extension for everyone.

Put Carmen on every managed Chrome without asking each person. About ten minutes.

Open the Google Admin console.

Open the Google Admin console. Go to Devices, Chrome, Apps and extensions, Users and browsers.

Managed Chrome

Google AdminCompany A

Devices
Chrome
Apps and extensions

Apps and extensions

Users and browsers

Manage apps for Company A.

Google Admin console · Illustrative

Pick the organisational unit.

Pick the organisational unit that should get Carmen.

Managed Chrome

Google AdminCompany A

Organisational units

Search organisational units

⌄ Company A ✓

Google Admin console · Illustrative

Add Carmen from the Web Store.

Click Add, then Add from Chrome Web Store. Search for Carmen Monitor and click Select. You can also choose Add Chrome app or extension by ID and paste ocfomobdgfdpfoplmmmocghhgkbniiia.

Managed Chrome

Google AdminCompany A

Add from Chrome Web Store

Carmen Monitor

Carmen MonitorSelect

Google Admin console · Illustrative

Set the installation policy.

Under Installation policy, choose Force install + pin to browser toolbar. Click Save.

Managed Chrome

Google AdminCompany A

Company A · Users and browsers

Carmen Monitor

Installation policyForce install + pin to browser toolbar

Save

Google Admin console · Illustrative

Run your first check

Open Chrome on a managed machine. Carmen is pinned. Each person still signs in once.

Your first check

Chrome toolbar

Illustrative

If it did not work

Carmen not appearing? On that computer, open chrome://policy and click Reload policies. ExtensionInstallForcelist should list ocfomobdgfdpfoplmmmocghhgkbniiia.
Not listed: check that Chrome management is on for that organisational unit and that the person is signed in to Chrome with their work account.
Listed but Carmen is turned off: check whether a policy that blocks extension permissions applies to it.