Hi I can't seem to get the aws_iot examples to work. On my latest attempt, I am working with the subscribe publish example. I am continually getting: I (4692) subpub: Connecting to AWS... I (11722) wifi: pm start, type:0 E (33342) subpub: Error(-28) connecting to asdf.iot.us-west-2.amazonaws.com:888...

I am looking for the certification guide (ESP32_Certification_and_Test_Guide__EN.pdf). I have seen it referenced in the forums but can't find it anywhere.