It's not in the base game, but there is a plugin that generates a map of your server and hosts it, called Bluemap [0]. It has an example. [1] I always toss it on the servers I host.

[0]: https://modrinth.com/mod/bluemap

[1]: https://bluecolored.de/bluemap/

A +1 for Bluemap. Plus because it's actually tied into the server[0], all your wacky mods have their blocks rendered correctly instead of confusing whatever map generator you're trying to use.

[0] Plus you can get live player positions, update markers in real time, etc.