Do I need to give an extra permission to upload images in Slack?

R./ Yes! Slack admins can grant that extra permission for us to process images securely via chat. 

How?

Simply re-authenticate the bot against Slack as if you were signing up for the first time. That will lead you to the integration process with Slack again where you'll be ask for the extra permission we need to process images securely.

If you're an admin, you can kickstart this process by following this link.

Once you're on this screen, just click "Allow" to grant your workspace the new permission. That's it! 🙌