Solution:
There are two APIs you can use depending on what you’re trying to accomplish. If you want to interact with a chatbot that has already been created you’d use the runtime API. Here is a link for the documentation to that.
http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/LexRuntime.html
If you need to create or modify a chatbot you’d use the Model Building Service API. Here is a link to that documentation.
http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/LexModelBuildingService.html