curl --request GET \
  --url https://xbt-mainnet.gomaestro-api.org/v0/esplora/tx/{txid}/rbf \
  --header 'api-key: <api-key>'

{
  "replacements": {
    "tx": {
      "txid": "2e95ff9094df9f3650e3f2abc189250760162be89a88f9f2f23301c7cb14b8b4",
      "fee": 1668,
      "vsize": 276.75,
      "value": 14849,
      "rate": 4.8242,
      "rbf": false,
      "fullRbf": true
    },
    "time": 1703240261,
    "fullRbf": true,
    "replaces": []
  },
  "replaces": [
    "3f4670463daadffed07d7a1060071b07f7e81a2566eca21d78bb513cbf21c82a",
    "92f9b4f719d0ffc9035d3a9767d80c940cecbc656df2243bafd33f52b583ee92"
  ]
}