I know that there are methods for sending a GET
request with a vanilla Alexa Lambda function, but does the same thing exist for POST
ing data to an HTTPS
URL?
I want to post data to a URL when the user fires a certain intent in my skill.
Yes, there are.
This is a tutorial on creating POST method with JSON payload from Amazon Doc
Personally, I would prefer to modulate and separate out the code dealing with HTTP out from the Alexa Skill, and put it into another Lambda function. Of course, it's totally optional, but here are my reasons:
If you are looking for some code example, I use to have a project that did similar job, hope you'll find the documentation helpful in some way.