Thanks. I used to spend too much back in the first three ancient months of the game but transitioned to mid spender. Then I became F2P for six months to allot the funds for clan prizes. Now, I might be back to casual purchases.
It's through the Twitch mobile app available on Google Play for Android users. I guess iPhone users have access to download the app, too, but I cannot say from experience. (É através do aplicativo móvel da Twitch disponível no Google Play para usuários Android. Acredito que usuários de iPhone também tenham acesso para baixar o aplicativo, mas não posso dizer por experiência própria.)