Hi,
To implement Audit Collection Services (ACS) in a System Center Operations Manager (SCOM) environment, you can install an ACS collector server in the main domain. It is not necessary to deploy ACS in the management server.
You can set up an ACS collector on a fresh server by following these steps:
Sign in to the server by using an account that has local administrative credentials.
On the Operations Manager installation media, run Setup.exe, and select Audit collection services.
Follow the instructions provided by the Audit Collection Services Collector Setup wizard to install an ACS collector and an ACS database. https://learn.microsoft.com/en-us/system-center/scom/deploy-install-acs?view=sc-om-2022
I hope this helps!