Your OAuth process is incorrect, and not as documented https://dev.twitch.tv/docs/authentication/getting-tokens-oauth#oauth-authorization-code-flow
If you’re using the Auth Code flow, step 1 is to send the user whose channel you wish to get permissions for to the OAuth link. You don’t make an axios request, you need to send the user to that actual URL.
If the user accepts, they’ll be redirected to your redirect URI, at which point your server can exchange the code for an access token as documented.
Once your server has exchanged the code for an access token and refresh token, then you can make API requests.