I copied this from what I mentioned in the comments. THIS IS FOR PC VERSION. For anyone having issues running the Among Us because they purchased it on the itch.io site, you MUST link the purchase to your Steam account. *NOTE: you do NOT have to repurchase the game* The steps below should help you out:
1. Go to 'my library' and click on Among Us. At the top of the page you will see "You Own This Game" and press the download button.
2. Scrolling down you should see a "claim steam key" click claim and you will have to put in a code given through an email address. Afterwards, you have to click that to reveal the steam key.
3. Open steam and on the top of the tab is 'Games' under the drop bar 'Activate a product on Steam'
4. Enter the steam key given from the 'Download Among US' given on the itch.io page.
5. Run the game on Steam (you will have to delete the old version and redownload it ON STEAM clicking the play or download button), this will enable you to play. When you do, the game will launch and you will be able to add your account, change your name, and chat.
For future reference, keep in mind that Questions & Support is for questions and support for Itch.io, and not for specific projects.
Since an answer is found already, I’ll leave it as-is in the hopes that it helps future-readers.
