After clicking the Claim button, it might take up to 10 minutes for the items to appear in your Steam inventory. If nothing shows up after 30 minutes, it's possible that your Steam account wasn’t connected to your Twitch account at the time you claimed the Drop. You can link your accounts at the top of this page and then check again to see if the missing Drops were rewarded. Please note that you must own Gray Zone Warfare on Steam to receive the items.