Request block candidate

Example response

{
  "msg": "0350e25cee8562697d55275c96bb01b34228f9bd68fd9933f2a25ff195526864f5",
  "b": 987654321,
  "pk": "0350e25cee8562697d55275c96bb01b34228f9bd68fd9933f2a25ff195526864f5",
  "proof": {
    "msgPreimage": "0112e03c6d39d32509855be7cee9b62ff921f7a0cf6883e232474bd5b54d816dd056f846980d34c3b23098bdcf41222f8cdee5219224aa67750055926c3a2310a483accc4f9153e7a760615ea972ac67911cff111f8c17f563d6147205f58f85133ae695d1d4157e4aecdbbb29952cfa42b75129db55bddfce3bc53b8fd5b5465f10d8be8ddda62ed3b86afb0497ff2d381ed884bdae5287d20667def224a28d2b6e3ebfc78709780702c70bd8df0e000000",
    "txProofs": [
      {
        "leaf": "cd665e49c834b0c25574fcb19a158d836f3f2aad8e91ac195f972534c25449b3",
        "levels": [
          [
            "018b7ae20a4acd23e3f1bf38671ce97103ad96d8f1c780b5e5e865e4873ae16337",
            0
          ]
        ]
      }
    ]
  }
}