This Lambda code example is for https://medium.com/tensult/make-a-website-dynamic-using-apis-f5d07def5d77

lambda-to-put-item-into-dynamodb.js

'use strict';  
const AWS = require("aws-sdk");  
const dynamo = new AWS.DynamoDB.DocumentClient();  
exports.handler = (event, context, callback) => {    
  const contactInfo = {};    
  contactInfo.Item = {      
    "email": event.email,      
    "name": event.name,      
    "message": event.message    
  };    
  contactInfo.TableName = "mywebsite-contact-us";                        
  dynamo.put(contactInfo, callback); 
};