The subscribe endpoint is called twice when first publishing a zap and then also twice when a zap is turned on.   It seems that the targetUrl changes each time you turn a zap on.  The Unsubscribe hook is not called when turning off a zap so managing this new updated targetUrl will be a nightmare.

{
  "authData": {
    "apiKey": ""
  },
  "inputData": {
    "save": true,
    "contacted": false,
    "quoting": false,
    "written": false,
    "nextyear": false,
    "followup": false,
    "appt": false
  },
  "inputDataRaw": {
    "appt": "false",
    "save": true,
    "quoting": "false",
    "written": "false",
    "followup": "false",
    "nextyear": "false",
    "contacted": "false"
  },
  "meta": {
    "isLoadingSample": false,
    "isFillingDynamicDropdown": false,
    "isTestingAuth": false,
    "isPopulatingDedupe": false,
    "limit": -1,
    "page": 0,
    "isBulkRead": false,
    "zap": {
      "help": l"This data structure is provided for backwards compatibility,", "and should not be relied upon in a Zapier integration."],
      "id": "subscription:31110385",
      "link": "https://zapier.com/app/editor/subscription:31110385",
      "live": true,
      "name": "A Zap",
      "user": {
        "timezone": "America/Denver"
      },
      "trigger": {
        "service": {
          "logos": {
            "16x16": "https://cdn.zapier.com/storage/photos/73a6433488cca7c5bd6ed9836fd6d9c8.png",
            "32x32": "https://cdn.zapier.com/storage/photos/73a6433488cca7c5bd6ed9836fd6d9c8.png",
            "64x64": "https://cdn.zapier.com/storage/photos/73a6433488cca7c5bd6ed9836fd6d9c8.png",
            "128x128": "https://cdn.zapier.com/storage/photos/73a6433488cca7c5bd6ed9836fd6d9c8.png"
          },
          "name": "A Zapier App"
        }
      },
      "action": {
        "service": {
          "logos": {
            "16x16": "https://cdn.zapier.com/storage/photos/73a6433488cca7c5bd6ed9836fd6d9c8.png",
            "32x32": "https://cdn.zapier.com/storage/photos/73a6433488cca7c5bd6ed9836fd6d9c8.png",
            "64x64": "https://cdn.zapier.com/storage/photos/73a6433488cca7c5bd6ed9836fd6d9c8.png",
            "128x128": "https://cdn.zapier.com/storage/photos/73a6433488cca7c5bd6ed9836fd6d9c8.png"
          },
          "name": "A Zapier App"
        }
      }
    }
  },
  "targetUrl": "https://hooks.zapier.com/hooks/standard/12316618/98e8a3ccdc264dd98d46111389f5f241/"
}