curl --request POST \
  --url https://testnet.walletkit.com/transactions/preview \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "network": "Ethereum",
  "from": "<string>",
  "unsigned_transaction": {
    "to": "<string>",
    "value": "<string>",
    "input": "<string>",
    "gasLimit": "<string>",
    "maxPriorityFeePerGas": "<string>",
    "maxFeePerGas": "<string>",
    "nonce": "<string>"
  }
}'

{
  "network": "Ethereum",
  "from": "<string>",
  "to": "<string>",
  "contract": {
    "network": "Ethereum",
    "address": "<string>",
    "type": "token",
    "name": "<string>",
    "logo_url": "<string>",
    "token": {
      "uuid": "<string>",
      "network": "Ethereum",
      "contract_address": "<string>",
      "name": "<string>",
      "symbol": "<string>",
      "decimals": 123,
      "display_decimals": 123,
      "logo_url": "<string>"
    },
    "nft": {
      "network": "Ethereum",
      "contract_address": "<string>",
      "name": "<string>",
      "symbol": "<string>",
      "image_url": "<string>"
    }
  },
  "function_name": "<string>",
  "arguments": {},
  "simulation": {
    "success": true,
    "asset_changes": [
      {
        "token": {
          "uuid": "<string>",
          "network": "Ethereum",
          "contract_address": "<string>",
          "name": "<string>",
          "symbol": "<string>",
          "decimals": 123,
          "display_decimals": 123,
          "logo_url": "<string>"
        },
        "nft": {
          "metadata": {
            "name": "<string>",
            "description": "<string>",
            "image": "<string>"
          },
          "owner_wallet_address": "<string>",
          "contract_address": "<string>",
          "token_id": "<string>"
        },
        "amount": "<string>",
        "raw_amount": "<string>",
        "from": "<string>",
        "to": "<string>"
      }
    ],
    "error": "<string>"
  }
}