What I initially had in mind was to create a custom interaction that displays real-world news.

I know how to create a custom interaction to display simple notifications, but I don’t know how to call an API in-game. I looked for code to access a URL but had no luck.

Is what I’m trying to do impossible?

(I used a translator, so I apologize if the sentences are awkward.)

I don't think so. TS3 environment is highly restricted to itself with exceptions for EA-approved destinations (such as the buy TS4 button).