Adding to my reply, Microsoft SQL supports TWO authentication types:
1- Windows Authentication (also known as "Trusted" or "Integrated")
These are simply local user or domain user accounts-- e.g. domain\user. This is essentially SQL server integrating with Windows, to authorize/authenticate users based on local or Windows AD domain accounts, for access control into SQL.
2- SQL Authentication
These are database accounts, in my own words, internal to the SQL server itself. The ITCM installer will create an account called ca_itrm, which will later be used by various CAF plugins, for access to the database.
Reference:
Authentication in SQL Server | Microsoft Docs
The ITCM installer requires the currently logged-on user to have admin access (sysadmin access), via there Windows Authentication to the SQL server.
After the product is setup, it will run on its own using ca_itrm and SQL authentication. The ca_itrm account is a "public" account with no admin privileges to the SQL server.
The Windows authentication is only required for the setup of the product.
-Brian