aws-sdk node equivalent of boto3 credentials python calls

Question

I have inherited a python lambda which I need to convert to node js. I am a bit stuck with the code that handles authentication and so I am wondering what the JS equivalent would be for the python code below:

import boto3
import json
import requests
from requests_aws4auth import AWS4Auth

region = "eu-west-2"
service = "es"

credentials = boto3.Session().get_credentials()
awsauth = AWS4Auth(credentials.access_key, credentials.secret_key, region, service, session_token=credentials.token)

r = requests.get(url, auth=awsauth)

Here is my work in progress at what seem to be relevant calls using the javascript aws-sdk:

import AWS from "aws-sdk"

const region = "eu-west-2"
const service = "es"

const credentials = AWS.Credentials().get()

const response = await fetch(url, {
  headers: { Authorization: credentials },
  credentials: "include"
})

I know the python code works, so I just need to convert it to JS. As you can see I'm not really sure what to do with credentials once I have it or what the equivalent of auth=awsauth would be within the fetch call. Any help would be much appreciated. Thank you!