Yes. Financial Management is not one of the Business major’s four concentrations, which are Data and Systems Management, Healthcare Management, Operations Management, and People and Culture Management. Nothing blocks a business major from earning it.
This minor has the heaviest overlap of the business minors, so the honest answer is that it may add very little. The business core already includes Principles of Accounting and Spreadsheet Skills. An Operations Management concentration adds Cost Accounting, Financial Management, and your Operations or Supply Chain course, which between them can leave Investing in Capital Markets as the only course you have not already taken.
Accounting majors have a specific rule. If you are an accounting major earning this minor, you must complete both BUS 318 Operations Management and BUS 312 Supply Chain Management rather than choosing one, which makes the minor seven courses instead of six.
Whether a single course can count toward both your major and this minor is a question for your advisor and the registrar. Given how much overlap there is here, get that answer before you declare.