flipkart api error{“code”:400,”message”:”Unable to process JSON”}

facing issue with the order fetching on flipkart seeller api i have already verified with the endpoint with the flipkart api i need the exatc one who had already working on it
POST https://api.flipkart.net/oauth-service/oauth/token?grant_type=client_credentials&scope=Seller_Api (OAuth Token)

• GET https://api.flipkart.net/sellers/v3/shipments/handover/counts?locationId=[REMOVED] (Vendor Pickup Count — WORKING)
• GET https://api.flipkart.net/sellers/v3/shipments?locationId=[REMOVED] (Shipments — FAILS)
• GET https://api.flipkart.net/sellers/v3/orders?locationId=[REMOVED] (Orders — FAILS)
• GET https://api.flipkart.net/sellers/v3/shipments?states=APPROVED,READY_TO_DISPATCH&locationId=[REMOVED] (Shipments with states — FAILS)
• `POST https://api.flipkart.net/sellers/v3/shipments/filter
  ”'{
  “type”: “preDispatch”,
  “filter”: {
  “states”: [
  “APPROVED”,
  “READY_TO_DISPATCH”
  ],
  “locationId”: “”
  },
  “pagination”: {
  “pageSize”: 50,
  “pageNumber”: 1
  }
  }
  Response:
  {“code”:400,”message”:”Unable to process JSON”}”’