boto sigv4 in python with Lambda

handler.py

import boto3
import json
import requests
from requests_aws4auth import AWS4Auth

def lambda_handler(event, context):
    signature = get_signature()
    return fetch(signature)
    
def get_signature():
    session = boto3.Session()
    credentials = session.get_credentials()
    sigv4auth = AWS4Auth(credentials.access_key, credentials.secret_key,
                         session.region_name, 'execute-api', session_token=credentials.token)
    return sigv4auth
    
def fetch(signature):
    url = <api gateway url>
    try:
        response = requests.request("GET", url, data={}, auth=signature, headers={
            'Content-Type': "application/x-amz-json-1.1"})
        json_data = json.loads(response.text)
        return json_data
    except Exception as e:
        print(e)

Ensure the Lambda functions role has the rights to execute the API