Trigger Lambda from SmartApp?

I’ve got a functionality that is already firmly planted in Lambda/Alexa. I wanted to trigger the existing Lambda from within SmartApp on device activation, such as motion.

I know I can accomplish with AWS API Gateway and get SmartApp to HTTPGet to the gateway. However, while trying to search the recommended approach, I see alot about using Lambda to host Smartapp and setting permissions in IAM for Smartthings. Like this one. Makes me think there may be a more direct way to trigger my lambda from Smartapp (without API Gateway).

Advice on that?

Well I figured out that the link talking about SmartApp/Lambda integration was in reference to the new Samsung/Smarthings Developer Workspace, which doesnt seem to have any relationship to the current Smartthings stuff. However, question remains. Is there a more direct way to trigger a lambda, other than via HTTP call?