Admin Login needed

I have created an interface for adding, deleting, and updating records on a website. I have placed those files, which all work, in a folder on the site called adminRecords. I need to create a login system so that the files in that folder cannot be accessed with the user logging in. I would like to make it so that if a user navigates to /adminRecords, they land on an index page that asks them for their credentials. Then they can access the add, delete, and update files which have already been built.