How do I find my product codes for my future giveaways?

Only some games have CD key but those aren't Steam redeemable.

Go In Steam-Settings-Ingame put V check (if don't have it) in "enable steam Overlay while ingame" and push OK
https://steamcdn-a.akamaihd.net/steam/support/faq/overlay_options.JPG
Then start the game
After the game is sart hold on shift button in keyboard and press Tab button in keyboard
this will make the steam ui overlay show to you and sometimes show also the key\code for the game.

Right Click-Manage-CD Keys still working for me in the latest beta version of steam btw i try it with farcry2.

p.s. it's splinter cell blacklist? 🤣

I´m not sure to which code you are referring to ..?
If you mean the AppID - you will find it with right click -> Properties -> Updates
Anything else I have no idea how that would help you with future giveaways ..

Are you talking about taking a game that you own on Steam and gifting your copy from your Steam account to someone else? If so, that is not possible. Once you activate a game on your account, you cannot remove it and give it to someone else.

https://i.ibb.co/8Nv5nyG/Screenshot-2021-08-30-213732.jpg

IF the game has a CD key.. Yes you can right click.. go to manage and click CD Keys

If you took first key from your library, I am afraid you will get red unrecieved mark, because these codes can't be used on another steams. These games with key are usually games from other platforms and can be reedemes on them. For example I gave to my friend my origins twin for Dragon Age (now should be these keys removed thanks to 1$EA pass).
So I am afraid these codes for your next giveaway you will find on sites like Fanatical or Humble, where can be games bought cheap in bundles.

Could I raffle off the steam games without using Humble Bunble? I am not interested in registering for these sites.