I need to implement something in the software layer or is it just infra?
Actually everything is ready. You just need to enable your application. Click on the project file of your ASP.NET MVC application and press F4. A screen like this should appear:
Change the field SSL Enabled for True. Your application will have two URL’s, one for HTTPS and the other for HTTP.
IIS Express installs a digital certificate for you. As it is self-signed, it works well while you are developing, but any external access will give validation problem.
The SSL configuration on IIS is here.
If buying a certificate is not an option, you can use that of Cloudflare, which is free. Simply transfer control of your DNS to it and set up SSL in the Cloudflare dashboard. In addition to SSL, Cloudflare also functions as a kind of a cache mixed with safety layer.