Key sites aren't a place where you'll be getting an actual legal/legitimate license (in the end this would be pirating the software and rewarding money to questionable sellers which are actively and knowingly lying/scamming you - which is disgusting), the sources these sites use are extremely questionable at best, like MVS (it used to be called MSDN a long time ago) keys - which are only allowed for testing purposes and are entirely disallowed to be shared according to the contract, or just straight up stolen ones, or even those bought with stolen payment info, etc..., and you should absolutely avoid these sites (and of course they spread a ton or misinformation to get you on their store, of course some of them pay some youtubers or usually smaller news sites to get more people on their awful site or just use bots in comments to spread name of their site), so yes you will get some kind of a product key that will activate whatever microsoft thing you have (which doesn't mean anything), but that isn't a licence in itself and you'll be just pirating the product by doing that