$ telnet 80
GET /index.html HTTP/1.1

then, press enter key twice. You should a response similar to the one below:

HTTP/1.0 302 Found
Date: Tue, 23 Feb 2021 14:01:28 GMT
OpenBSD httpd
Connection: close
Content-Type: text/html
Content-Length: 486

<!DOCTYPE html>
<meta charset="utf-8"> 
<title>302 Found</title>
<style type="text/css"><!--
body { background-color: white; color: black; font-family: 'Comic Sans MS', 'Chalkboard SE', 'Comic Neue', sans-serif; }
hr { border: 0; border-bottom: 1px dashed; }
@media (prefers-color-scheme: dark) {
body { background-color: #1E1F21; color: #EEEFF1; }
a { color: #BAD7FF; }
<h1>302 Found</h1>
<address>OpenBSD httpd</address>
Connection closed by foreign host.