Authentication for Blazor server app

Hi All,

I am learning and developing blazor. So I need some assistance.

I want to add authentication after the successful creation of blazor server app. I know there is an option to change the authentication while creating a new project as shown in the screenshot attached below but I have a blazor server app without authentication and want to add this later.

Kindly assist me how can I do this.

Regards
Naresh