In asp.net core https is enabled by default. The HttpsRedirection middleware class provides the necessary functionality to enforce redirection from http to https.
HTTPS is a network protocol used to serve up web pages. HTTPS, or HTTP Secure, was designed to secure communications between a client and the HTTP server. It is a protocol that uses a secure connection to transfer data over the internet.
HTTP & HTTP/2 are both application level protocols that utilize a lower level protocol like TCP to talk on the Internet. The protocol of the Internet is TCP over IP over Ethernet.