UpdateAccount.js

var docClient = new DOC.DynamoDB();
var params = {};
params.TableName = "accounts";
params.Key = {accountId: event.accountId};
params.AttributeUpdates = {
  website: {PUT: "update", Value: event.website}
};
docClient.updateItem(params, function (err, data) {
  if (err) {
    console.log(err, err.stack);
    context.done("Error while creating account: " + err);
  } else {
    console.log("account updated", user.email);
    context.done(null, {accountId: event.accountId});
  }
});