curl --request POST \
  --url https://tars.loopscale.com/v1/markets/creditbook/sell \
  --header 'Content-Type: application/json' \
  --header 'user-wallet: <user-wallet>' \
  --data '
{
  "loan": "<string>",
  "oldStrategy": "<string>",
  "newStrategy": "<string>",
  "sellParams": {
    "ledgerIndex": 123,
    "expectedSalePrice": 123,
    "assetIndexGuidance": [
      123
    ]
  }
}
'

{
  "message": "<string>",
  "signatures": [
    {
      "publicKey": "<string>",
      "signature": "<string>"
    }
  ]
}