config async problem when creating endpoint

[RwGrid]

create_model = sagemaker_client.create_model(
ModelName = 'tritoninferencesasync',
ExecutionRoleArn = role,
PrimaryContainer= container)

create_endpoint_config_response = sm_client.create_endpoint_config(
EndpointConfigName='endpointconfigsingleasnyc',
ProductionVariants=[
{
"VariantName": "variant1",
"ModelName": 'tritoninferencesasync',
"InstanceType": "ml.m5.xlarge",
"InitialInstanceCount": 1,
}
],
AsyncInferenceConfig={
"OutputConfig": {
"S3OutputPath": "s3://allinferences/yy/xx"
},
"ClientConfig": {"MaxConcurrentInvocationsPerInstance": 4},
},
)
endpoint_name='tritonendpointsasync'
create_multi_endpoint = sagemaker_client.create_endpoint(
EndpointName = endpoint_name,
EndpointConfigName = 'endpointconfigsingleasnyc')

i get this error : botocore.exceptions.ClientError: An error occurred (ValidationException) when calling the CreateEndpoint operation: One or more endpoint features are not supported using this configuration
when i remove the async 'AsyncInferenceConfig' , it works, but i want an async endpoint because my payload is above 5 mb, its a numpy array of image of 50 + mb , so i need async, the container is triton