curl --request GET \
  --url https://api.circle.com/v1/exchange/stablefx/signatures/presign/{tradeId} \
  --header 'Authorization: Bearer <token>'

{
  "typedData": {
    "domain": {
      "name": "Permit2",
      "chainId": 11155111,
      "verifyingContract": "0xffd21ca8F0876DaFAD7de09404E0c1f868bbf1AE"
    },
    "types": {
      "EIP712Domain": [
        {
          "name": "<string>",
          "type": "<string>"
        }
      ],
      "Consideration": [
        {
          "name": "<string>",
          "type": "<string>"
        }
      ],
      "TraderDetails": [
        {
          "name": "consideration",
          "type": "Consideration"
        },
        {
          "name": "recipient",
          "type": "address"
        },
        {
          "name": "fee",
          "type": "uint256"
        },
        {
          "name": "authorizer",
          "type": "address"
        }
      ],
      "TokenPermissions": [
        {
          "name": "<string>",
          "type": "<string>"
        }
      ],
      "PermitWitnessTransferFrom": [
        {
          "name": "<string>",
          "type": "<string>"
        }
      ]
    },
    "primaryType": "PermitWitnessTransferFrom",
    "message": {
      "permitted": {
        "token": "0x3600000000000000000000000000000000000000",
        "amount": 429000000
      },
      "spender": "0xa8f94168b4981840ba27d423f4ad6332bedee006",
      "nonce": 309585810,
      "deadline": 1770302983,
      "witness": {
        "consideration": {
          "quoteId": "<string>",
          "base": "<string>",
          "quote": "<string>",
          "baseAmount": "<string>",
          "quoteAmount": "<string>",
          "maturity": 1716153600
        },
        "fee": 80000,
        "authorizer": "0x0000000000000000000000000000000000000000",
        "recipient": "0x1f531ce3c418bbd830d06138a9e5b5eacfdfb3d6"
      }
    }
  }
}