'redirect_uri' could not be validated

Hey Y’all. I’m trying to set up a smartapp and I’m getting a 'redirect_uri' could not be validated error when I click on my https://api.smartthings.com/oauth/authorize ?… url. I’m pretty sure I’m encoding the url correctly, do I need to verify a domain or something?

It works if I don’t include the redirect_uri param but then it ends in a 404 page. :frowning:

SmartThings should send a request to your server with a url that you have to open in the browser to verify that it is indeed your server it is talking to. Could be the issue, have a look at this post Simple SmartApp Tutorial (SmartApp SDK) - #25 by Warren1