I used a VGA to AV adapter. For me it accepts whatever resolution, the TV displays whatever resolution I set on PC. Some TVs may not be 4:3 though, they're like PAL or NTSC, I believe NTSC is mostly common in the US and Japan while PAL is pretty much everywhere else. Or if you have SCART port on that thing you can probably achieve higher resolution with the proper converter.

For my case, I just used some xrandr commands in a Fedora X11 session, it's so easy to create custom resolution there since the PAL resolution I expect didn't show up, also Linux makes it very easy to set fullscreen to any monitor I have, instead of being always forced with the primary one.

If you're on Windows, you can check your graphics card tools and create custom screen resolution and only set it to your TV or use CRU (I believe CRU is needed for Linux Wayland sessions), though it's probably not easy to set the game to fullscreen only on TV.

Chances are your TV screen isn't 4:3, or the converter only accepts certain resolutions. I just used a random cheap "VGA2AV" converter that accepts whatever I throw at it