First register a new Slack Application.

Slash commands

• Navigate to Features -> Slash commands in the sidebar

• Click "Create a new command"

• Fill in the form like so, replacing the domain with your own and hit "Save"

Slash commands setup

• Next, navigate to Features -> Interactivity & Shortcuts in the sidebar

• Enable the interactivity toggle and fill in the request url, again replacing the domain with your own

• No other settings need changing on this screen, hit "Save"

Slack interactivity setup

• Install the app in your workspace

• This should be enough for the /outline slash command to work correctly

Link unfurling

• Navigate to Features → OAuth & Permissions

• Under “Redirect URLs” ensure the following url exists:

  • https://yourdomain.com/auth/slack.commands

Posting to channels

• Navigate to Features → OAuth & Permissions

• Under “Redirect URLs” ensure the following url exists:

  • https://yourdomain.com/auth/slack.post