If you are on a mac, and you are trying to do what I think you mean... System Preferences -> Keyboard -> Text -> Use Smart Quotes and Dashes @mingp

Sorry if that isn't useful!

@threequal Yes, I’m on OSX. And I have that setting disabled at the OS level. But, I think Slack has its own setting. Previously, I remember it being in Preferences, but I can’t find it any more, and I’m not sure if it got removed.