Serverless Call IAM Authenticated AWS API Gateway

lambda.py

from botocore.vendored import requests
from requests_aws4auth import AWS4Auth
import os

URL = "https://myurl.com"
REGION = 'ap-southeast-2'
METHOD = 'GET'
SERVICE = 'execute-api'

def handler(event, context):
    auth = AWS4Auth(
        os.environ['AWS_ACCESS_KEY_ID'],
        os.environ['AWS_SECRET_ACCESS_KEY'],
        REGION,
        SERVICE,
        session_token=os.environ['AWS_SESSION_TOKEN']
    )
    r = requests.request(METHOD, URL, auth=auth)

serverless.yml

service: sample-service
provider:
  name: aws
  runtime: python2.7
  region: ap-southeast-2
  iamRoleStatements:
    - Effect: Allow
      Action: "execute-api:*"
      Resource: "*"