curl --request GET \
  --url https://api.getoutbox.ai/module/instance/list \
  --header 'Authorization: <api-key>'

[
  {
    "id": "<string>",
    "icon": "<string>",
    "instance_name": "<string>",
    "description": "<string>",
    "activation_type": "<string>",
    "custom_params": {},
    "variables": [
      {
        "name": "<string>",
        "description": "<string>",
        "type": "<string>",
        "required": true,
        "preset": true
      }
    ]
  }
]