API Contracts - Staging - 'select' API getting 500 Response

[inventionsbyhamid]

Hi. I have successfully done initial staging setup for buyer app and search API is working fine. When I try 'select' API on staging I am getting 500 Response
{ "error": "Something went wrong. Please try again" }

For staging I am using https://ref-app-seller-staging-v2.ondc.org seller to try the select API.

I am sharing the curl request that I tried.
curl --location 'https://ref-app-seller-staging-v2.ondc.org/select' \ --header 'Authorization: Signature keyId="sasta.zone|ddcf5fe4-2494-4d9d-ad39-d1ed7c8e41a5|ed25519",algorithm="ed25519",created="1706621761",expires="1706625361",headers="(created) (expires) digest",signature="uUTFW0z9Drzn/IDcAuarzprLR+H7FXl/taoZkUrUYyK6JW9NyDsn4xqgKXY2GduVCArTAIBmH9ZapOkYR+cMCw=="' \ --header 'Content-Type: application/json' \ --data '{"context":{"domain":"ONDC:RET11","country":"IND","city":"std:011","action":"select","core_version":"1.2.0","bap_id":"sasta.zone","bap_uri":"https://ef41-122-161-50-114.ngrok-free.app/bapl/","bpp_id":"ref-app-seller-staging-v2.ondc.org","bpp_uri":"https://ref-app-seller-staging-v2.ondc.org","transaction_id":"1234","message_id":"abcd","timestamp":"2024-01-30T11:11:35.097Z","ttl":"PT24H"},"message":{"order":{"items":[{"id":"d064b7ad-0031-4a2c-b8a7-187cd423be77","quantity":{"count":1}}]}}}'

Also wanted to ask what is the recommended local setup during development to test callbacks ? I am currently using ngrok to expose my local server and providing that URL in bap_uri which is working fine for search API.