How to get free chat on among us is that you must have the game on steam and make sure that the game is updated then you sign in to among us then you go to settings, next click data, last step is if you see the chat type light up then you click that and it has to say free or quick chat only if you are signed in to among us on steam
You can also have the game on Epic or a variety of mobile platforms. The itch.io PC version is the only one you can't create an account in.
And the devs have said they're looking into fixing that in future, but no timeframe has been promised for when it might happen. Given the issues I've seen with Steam since late 2019, I can see a valid argument for Google Play to be a better source of PC games.