How to stop getting Lambda Invocation output email from SNS whereas I want to get email with custom content

I was trying to setup EC2 start/stop/reboot email notification using EventBridge-Lambda-SNS. So when Cloudtrail will detect the API RunInstances/StopInstances/RebootInstances, that will match eventbridge rule condition which invokes lambda function to send a customized email body through sns topic.

Function Code:

import os
import json
import boto3

def lambda_handler(event, context):
        
        EventID = event['detail']['eventID']
        Account = event['account']
        Timestamp = event['time']
        Region = event['region']
        InstanceID = event['detail']['requestParameters']['instancesSet']['items'][0]['instanceId']
        EventName = event['detail']['eventName']
        SourceIP = event['detail']['sourceIPAddress']
        InitiatedBy = event['detail']['userIdentity']['arn']
        
        if EventName == 'StopInstances':
            msg_status = 'stopped'
        elif EventName == 'StartInstances':
            msg_status = 'started'
        elif EventName == 'TerminateInstances':
            msg_status = 'terminated'
            
        body = f'Hi Team, \n\nThis is to inform you that EC2 instance with {InstanceID} is {msg_status}.Please find below information. \n\nEventID = {EventID}, \nAccount = {Account}, \nTimestamp = {Timestamp}, \nRegion = {Region}, \nInstanceID = {InstanceID}, \nEventName = {EventName}, \nSourceIP = {SourceIP}, \nInitiatedBy = {InitiatedBy} \n\nRegards,\nCloud Team'
        
        sns_client = boto3.client('sns')
        snsarn = os.environ['snsarn']
        
        res = sns_client.publish(
            TopicArn = snsarn,
            Subject = f'Alert - {InstanceID} is {msg_status}',
            Message = str(body)
            )

Then I tested this function by starting/stopping instance and I got expected email body. But apart from this I am getting Lambda invocation output JSON content in email which I don't want.

Expected:

Hi Team,
    
This is to inform you that EC2 instance with i-0d8219ba97c61c428 is started. Please find below information.
    
EventID = 9b07afa3-222c-4632-9dc9-bfa145ddb573,
Account = 12345678910,
Timestamp = 2023-08-13T04:49:49Z,
Region = us-east-1,
InstanceID = i-0d8219ba97c61c428,
EventName = StartInstances,
SourceIP = <IP>,
InitiatedBy = arn:aws:iam::12345678910:root

Regards,
Cloud Team

Sample Invocation Output Unexpected:

I am getting another email of below looking content. Here I pasted sample one(copied from documentation), but yes exactly same json structure I receive which I don't want. Please help me how to stop getting this email.

{
    "version": "1.0",
    "timestamp": "2019-11-14T18:16:05.568Z",
    "requestContext": {
        "requestId": "e4b46cbf-b738-xmpl-8880-a18cdf61200e",
        "functionArn": "arn:aws:lambda:us-east-2:123456789012:function:my-function:$LATEST",
        "condition": "RetriesExhausted",
        "approximateInvokeCount": 3
    },
    "requestPayload": {
        "ORDER_IDS": [
            "9e07af03-ce31-4ff3-xmpl-36dce652cb4f",
            "637de236-e7b2-464e-xmpl-baf57f86bb53",
            "a81ddca6-2c35-45c7-xmpl-c3a03a31ed15"
        ]
    },
    "responseContext": {
        "statusCode": 200,
        "executedVersion": "$LATEST",
        "functionError": "Unhandled"
    },
    "responsePayload": {
        "errorMessage": "RequestId: e4b46cbf-b738-xmpl-8880-a18cdf61200e Process exited before completing request"
    }
}