Creating a multi-room website that has a unique shareable url for each room

I am interested in creating a web application where a user can click a button, and it will create a room for them and redirect them to a unique URL which they can send to other users to join as well.

A example would this would be lichess.org or meet.google.com. On each website, after a game or meeting is created, the site redirects the user to a short, unique url that can be shared so that others can join the same game/meeting.

How can someone accomplish this task? What technology can be used to have a client join a room after visiting this unique link?

In my mind, a possible solution would be to create a file with the name of the url nonce, and that file would be filled with an HTML template for what the "room" should look like. But I do not understand how I can handle requests to this unique URL (is this done using something like Flask?), and also I cannot figure out how I would be able to serve an HTML file at this unique shareable URL without having the url end in ".html". It seems like my approach in thinking about this is completely wrong, and I would appreciate any technologies/frameworks/architectures/strategies you can point me to.