Connect to Redshift (in private Subnet) using Lambda

I have a Redshift cluster in private subnet and i am using Pyscopg2 library to connect to it from Lambda . I have deployed the Lambda inside the VPC and subnets and security group appropriately.

When I use the following code to connect ,

try:
    client = boto3.client('redshift')
    creds = client.get_cluster_credentials(
      DbUser=REDSHIFT_USER,
      DbName=REDSHIFT_DATABASE,
      ClusterIdentifier=REDSHIFT_CLUSTER,
      DurationSeconds=3600)
  except Exception as ERROR:
    print("Credentials Issue: " + ERROR)
  try:

    conn = psycopg2.connect(
      dbname=REDSHIFT_DATABASE,
      user=creds['DbUser'],
      password=creds['DbPassword'],
      port=REDSHIFT_PORT,
      host=REDSHIFT_ENDPOINT)
  except Exception as ERROR:
    print("Connection Issue: ")
    raise

I get the folliowing error

{
  "errorMessage": "FATAL:  no pg_hba.conf entry for host \"::ffff:10.209.4.117\", user \"IAM:awsuser\", database \"dev\", SSL off\n",
  "errorType": "OperationalError",

I have solved this error in SQL clients by adding the following properties AuthMech=REQUIRE&ssl=TRUE

However , i am not sure how can i make the lambda code connect to Redshift.