You simply expose jellyfin to the internet like you would with any other service. Why did you think it specifically wouldn’t work over the internet for jellyfin?

The entire point of jellyfin is being able to remotely access media (with an good interface and functionality). What do you mean by remote access?

Capybaras

If you’re forced to watch ads to watch the video, it’s not free unless your time is worthless. Although, ads on YouTube videos can be circumvented. Thereby practically free.

The amount of effort he puts into practically free videos on the internet is amazing.