Recieving 403 error upon calling post request to api gateway

Hi, currently im trying to invoke an api gateway that invokes a lambda function. Im doing this all from a local development server, not sure if thats the problem but i think i should be able to do so eitherway let me know if not. But im using django for my apps backend and thats where im running into the issue. i recive the response itself but i also recieve a 403 code. the response is just null however. here is my code for my django view:

@api_view(['POST'])
def invoke_endpoint(request):
 #call lambda function in the cloud to invoke sagemaker endpoint for response generation
 input = request.data.get('query','')
 lambda_payload = {
 "queryStringParameters": input,
 }
 
 session = Session()
 credentials = session.get_credentials()
 aws_access_key = credentials.access_key
 aws_secret_key = credentials.secret_key
 region = session.region_name
 service = 'execute-api'
 endpoint = 'endpoint-link/generatearesposne'
 auth = AWS4Auth(aws_access_key, aws_secret_key, region, service)
 
 payload_bytes = json.dumps(lambda_payload).encode('utf-8')
 r = requests.post(endpoint, data=payload_bytes, auth=auth)
 response_payload = r.json()

 print(r)
 
 return JsonResponse({'response-payload': response_payload})

i am providing the auth to be able to call the function, i also have the aws cli setup and am configured to a user that has permissions to use lambda, sagemaker and api gateway. im not sure what else i need or if im making some sort of mistake here. fairly new user of AWS so im not sure.

my response looks like this: <Response [403]>