Google G2A or CDKeys that will take you to their stores.
If you werent aware, those are fairly shady sites to use.
Both of those are considered 'grey market' since they do not source the keys they sell from the developers or publishers of the games they sell. They sometimes resort to rather nefarious methods to obtain the keys they sell.
Specifically for G2A, there is an option at checkout that asks if you want to buy insurance on the key you purchased from them... in case it doesnt work.
Logically speaking, are you filled with confidence if a key seller wants you to buy insurance to guarantee the key you buy will work?
Oh, and if you buy that insurance... it was automatically recurring whether you shop there in the future or not. And this used to be how you would cancel it:
https://imgur.com/gallery/PUwPC
Relating it to sim racing... G2A, CDKeys, Kinguin, etc. are about the same as a 'modder' stealing content from another game, doing a slight touch up, and then releasing it for another game while calling it their own.
Yes, some of those websites have cheaper games occasionally, but I would highly recommend sticking to an authorized retailer.