curl --request GET \
  --url https://api.planetscale.com/v1/organizations/{organization}/databases/{database}/branches/{branch}/extensions \
  --header 'Authorization: <api-key>'

[
  {
    "id": "<string>",
    "name": "<string>",
    "description": "<string>",
    "internal": true,
    "url": "<string>",
    "parameters": [
      {
        "id": "<string>",
        "name": "<string>",
        "display_name": "<string>",
        "namespace": "patroni",
        "category": "<string>",
        "description": "<string>",
        "extension": true,
        "internal": true,
        "parameter_type": "array",
        "default_value": "<string>",
        "value": "<string>",
        "required": true,
        "created_at": "<string>",
        "updated_at": "<string>",
        "restart": true,
        "max": 123,
        "min": 123,
        "step": 123,
        "url": "<string>",
        "options": [
          "<string>"
        ],
        "actor": {
          "id": "<string>",
          "display_name": "<string>",
          "avatar_url": "<string>"
        }
      }
    ]
  }
]