Fastest cleanest way if you’re a Terminal Enjoyer™ is with curl:
curl -I https://henry.codes/
The -I flag, short for --head, includes only HTTP headers in the output. Here’s a tidy little curl cheat sheet for you; don’t spend it all in one place.
But if you prefer using a browser dev inspector, you can go Inspector > Network > HTML > [the current page] and scroll to Response Headers.
