I am using account linking with Alexa and getting an accessToken back. I am authenticating using AWS Cognito. My assumption is that accessToken is the token for AWS Cognito - but how do I use it? I need to get the CognitoUser information. I've seen examples using the Facebook SDK and it's stupid simple to say Fb.setToken(accessToken), but I can't find the equivalent for Cognito. What am I missing?!