When you integrate Windmill with Slack all that will happen initially is Windmill will show up as an “App”.
It will not join any channels and it will not read any messages. In order to experience the power of Windmill and Slack, you should add the Windmill app to individual channels.
You can learn more here: https://help.gowindmill.com/en/articles/8835301-adding-a-slack-channel-to-windmill
Our recommendation for new Windmill users is to have Windmill "Autojoin all public channels". In order to do this, as an Admin:
1) Go into Windmill
2) Select Settings
3) Select Connections
4) Select Slack
5) Go to Settings and select "Autojoin all public channels)