Amazon SP-API getOrder API empty response with 200 response code

Question

GetOrder API End Point & param

https://sellingpartnerapi-na.amazon.com/orders/v0/orders/111-6934537-0********

orderId = 111-6934537-0********

getOrder API Reference :

https://github.com/amzn/selling-partner-api-docs/blob/main/references/orders-api/ordersV0.md

Getting following response (in postman) :

{
    "payload": {}
}

I followed the instruction given in doc https://github.com/amzn/selling-partner-api-docs/blob/main/guides/developer-guide/SellingPartnerApiDeveloperGuide.md

My Header info :

x-amz-access-token:Atza|Xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Authorization :

For Authorization using AWS Signature (Postman Authorization Tab). The required params to generate signature is below (it's working):

AccessKey : AKIAZB**********

SecretKey : 50h4F1IEPr*********************

AWS Region : us-east-1

Service Name : execute-api