Unfortunately getting Alexa to speak the result of a web request isn't supported. For that matter, IFTTT won't do what you want either -- it drops the response on to the floor rather than allowing you to pass it to another step.
You could write your own home automation skill for Alexa, which would enable your use case. This is pretty involved, though, and requires you to integrate with an oAuth provider and write code. Not sure whether you were looking for something simpler. This blog post explains the steps.