We have added a button if you are logged in to the page at twitch.facepunch.com named "Check For Missing Drops" which should issue the missing items to your Inventory.
Twitch account is already linked to a Steam account.
Once you have followed the above instructions head back to twitch.facepunch.com and sign in using your new Twitch and Steam details.
Is there any way to check my progress towards the next drop? What if I missed the drop?
You can track your progress on the Twitch Drops Inventory page.
How long does it take for drops to show up in my Steam inventory?
It can take up to 1 hour after pressing the Claim button for items to show up in your Steam inventory. If the item does not show up after 30 minutes then your Steam account may not have been linked to your Twitch account when you claimed the drop. You can link your accounts on the top of this page and then click the button to check for missing drops to attempt the reward again. You will need to have Rust in your Steam library to receive the items.