i just randomly got a 'booster pack' for this game, but i dont even know what this is, like what?

isn't UC basically 2 with more content? + achievements

i love this game but i have the issue of being to good of a driver. Every race every class I just leave everyone miles behind in like a minuet to at most a lap and then im just driving alone the rest of the time unless i screw up and crash. Which sucks cause i wanna be part of the destruction. Its probably cause ive played this game since i was 10 years old and have beaten it once before so i know all the tracks by heart but still i need a harder difficulty....

When I launch the mod manager on my Steam Deck the list is always empty, no matter what workshop mods I subscribe to. I have the same problem in FlatOut 2.

How do you actually get it? I've been following different guides but no luck.