curl --request GET \
  --url https://external-api.kalshi.com/trade-api/v2/communications/block-trade-proposals \
  --header 'KALSHI-ACCESS-KEY: <api-key>' \
  --header 'KALSHI-ACCESS-SIGNATURE: <api-key>' \
  --header 'KALSHI-ACCESS-TIMESTAMP: <api-key>'

{
  "block_trade_proposals": [
    {
      "id": "<string>",
      "proposer_user_id": "<string>",
      "buyer_user_id": "<string>",
      "seller_user_id": "<string>",
      "market_ticker": "<string>",
      "price_centi_cents": 123,
      "centicount": 123,
      "expiration_ts": "2023-11-07T05:31:56Z",
      "status": "<string>",
      "created_ts": "2023-11-07T05:31:56Z",
      "updated_ts": "2023-11-07T05:31:56Z",
      "buyer_accepted": true,
      "seller_accepted": true,
      "buyer_subtrader_id": "<string>",
      "seller_subtrader_id": "<string>",
      "buyer_accepted_ts": "2023-11-07T05:31:56Z",
      "seller_accepted_ts": "2023-11-07T05:31:56Z",
      "executed_ts": "2023-11-07T05:31:56Z",
      "buyer_order_id": "<string>",
      "seller_order_id": "<string>"
    }
  ],
  "cursor": "<string>"
}