The Microsoft Defender for Identity (MDI) sensor can be downloaded from the Microsoft 365 Defender portal. The MDI sensor installation package is the same for Domain Controllers, ADFS and ADCS. If you have previously downloaded the package, you can use this for the installation, although I would recommend downloading the latest version for any new deployments.
Download steps
Use the menu on the left to scroll down to Settings.
Select Identities on the Settings page.
This should take you to the Sensors page. From here select Add sensor.
You can download the installer on the next window. The Access key will be used during the installation.
The installation package will be downloaded as a ZIP file.
The ZIP file can now be copied to the target server and extracted to execute and complete the MDI sensor installation.
Access key
The access key will only be used during the installation of a new sensor. You can install the MDI sensor using this key, with a new download or a previously downloaded package.
Once you regenerate the key, any new installations with the old access key will fail and thus you would need to use the new access key to complete the installation.
Regenerating the access key will not affect any sensors that are already installed and operational.