How to get Schema Example working?

Hi,
I’ve been following the instructions from https://smartthings.developer.samsung.com/docs/getting-started/st-schema.html, but when I finished “adding the device”, nothing shows up. According to the code from [Step 3], the app should automatically create a “Kitchen Light” virtual device using my AWS lambda function. So why aren’t any devices showing up? I’d appreciate any help

Additional info about what I’ve done:

  1. I created an IAM user named “default” with “AWSLambdaFullAccess” policy @ https://console.aws.amazon.com/iam/home?#/users. This was so I could use the below command for the “–profile default”:

aws lambda add-permission --profile default --function-name demoSTSchema --statement-id smartthings --principal 148790070172 --action lambda:InvokeFunction

  1. To get a client id & secret (for testing), I used “Login with Amazon”. I created a new security profile @ https://developer.amazon.com/loginwithamazon/console/site/lwa/overview.html.
    The Authorization URL is: https://www.amazon.com/ap/oa
    The Token URL is: https://api.amazon.com/auth/o2/token
    The Scope is: profile

  2. My lambda function policy & execution role are shown in the following image