How can I use existing ASP.NET Membership data in

Question

I am starting a new .Net Core Web application. And I want to use the authentication tables (aspnet_Users, aspnet_Membership etc) that already exist in our database. But I am not sure how to do it.

Upon creating the project, I select "Individual User Accounts" option for authentication. Then I need to choose between "Store user accounts in-app" and "Connect to existing store in the cloud".

It seems like none of them suits my need.