lambda invoking sagemaker endpoint

can anyone help me, i am trying to send my parameters, but i am not able to get the output

import io import boto3 import json import csv

ENDPOINT_NAME = os.environ['ENDPOINT_NAME'] runtime= boto3.client('runtime.sagemaker')

def lambda_handler(event, context): print("Received event: " + json.dumps(event, indent=2))

data = json.loads(json.dumps(event))
payload = data['bmi'] +data['weight'] +data['height'] + data['hsi']
print(payload)
response = runtime.invoke_endpoint(EndpointName=ENDPOINT_NAME,
                                   ContentType='text/csv',
                                   Body=payload)
print(response)
result = json.loads(response['Body'].read().decode())

return result

{"data":"2,4,4,18"} when i am sending parameters like this it is working,but i want to send the parameters like below format.

{ "bmi":0, "weight":0, "height":0, "hsi":0, }