Create a giveaway for a game that is not on the list

It looks like the game was removed from Steam. I think the correct thing to do is created a support ticket with the button on the top of the page (direct link). Select the category "Add game to list" and let them know what game you want to create a giveaway for. They should be able to manually add the game back to the site so everyone can create giveaways again.

Good luck ;)

Note for removed games you won't get any CV anyway. There is an orphan key thread you could try posting on instead.