https://dev.twitch.tv/docs/authentication/getting-tokens-oauth#oauth-authorization-code-flow Steps 3 and 4 explain what to do with the code and how to exchange it for OAuth tokens.
https://dev.twitch.tv/docs/authentication/getting-tokens-oauth#oauth-authorization-code-flow Steps 3 and 4 explain what to do with the code and how to exchange it for OAuth tokens.