This suggests you have not selected Extension Configuration Service as your selected configuration system, but then the API call wouldn’t get new data… So I don’t think it’s that
Your front end call should be just
window.Twitch.ext.configuration.set('broadcaster', 'VERISIONHEREORBLANK', 'OPTIONHERE');
And the user doing the call must be the broadcaster for the channel
bind a onError to look for errors and/or use inspector to trace the call