For mac you can get dev tools by either launching slack with export SLACK_DEVELOPER_MENU=true; open -a /Applications/Slack.app to make this persistent you

For mac you can get dev tools by either launching slack with export SLACK_DEVELOPER_MENU=true; open -a /Applications/Slack.app to make this persistent you can use. launchctl setenv SLACK_DEVELOPER_MENU true and then right click and inspect element and add the scripts