curl --request POST \
  --url https://tars.loopscale.com/v1/markets/creditbook/build \
  --header 'Content-Type: application/json' \
  --header 'user-wallet: <user-wallet>' \
  --data '
{
  "steps": [
    {
      "params": {}
    }
  ],
  "loan": "<string>"
}
'

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