So i've been wanting to speedrun this game but while rewatching world record i found out that the version world record was using was different so i was just wanting to ask if anyone has a link i can use for the correct version, Thank you.

Here's where you can play the up-to-date version of the game:

https://www.numuki.com/game/unfair-mario/

Since most major browsers stopped supporting the Flash Player Plugin, it is probably one of the fewest places where you can play it nowadays.

I'd say personally MiniPlay is the safest site to play it on https://www.miniplay.com/game/unfair-mario

I don't think they're asking for a safe site, it's talking about different version that might affects the map of a level, see another forum for the same topic: https://www.speedrun.com/unfairmario/forums/zttsp