Create Webhook Subscription

curl --request POST \
  --url https://auth.exchangeratesapi.com.au/api/webhook-subscriptions \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "url": "https://hooks.example.com/rba",
  "currencies": [
    "USD",
    "JPY"
  ],
  "description": "Prod hook"
}
'

{
  "success": true,
  "signingSecret": "3f9c4e2a1b7d8f60a5c3e1d9b2f4a6c83f9c4e2a1b7d8f60a5c3e1d9b2f4a6c8",
  "warning": "Store this signing secret securely. It will not be shown again.",
  "subscription": {
    "id": "a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6",
    "url": "https://hooks.example.com/rba",
    "currencies": [
      "USD",
      "JPY"
    ],
    "description": "Prod hook"
  }
}