Something easy (Not available in China)

Generally, you shouldn't post the solution. The point of invite giveaways is to avoid bots and have fun solving. If you post it, there's less fun for many.

Hey Dante, most times in the Puzzles / Events tab (or sometimes in other places), when you get a 5-digit code, you have to put it into a giveaway link to access the games being given away, this is the format:

https://www.steamgifts.com/giveaway/xxxxx/

I'd suggest deleting this comment and inserting the codes you posted!