Help with filter configutation

Hi, I’m setting up Haaska and have been trying to find instructions on how to apply a filter on the home assistant side so that only selected devices are exposed to Alexa. I’ve seen some related threads here but none of them point to any instructions. I’ve tried googlling “home assistant haaska filter” but that only showed threads that were not helpful. I get that I should be able to create filters in configuration.yaml under cloud: alexa: - if this is correct what exactly is the factor that ties the keyword alexa: to the lambda function making requests from the cloud?
Any pointers to relevant documentation will be appreciated.

Did you ever figure this out? Just wasted a whole day trying everything.