curl --request GET \
  --url https://api.agg.market/apps/{appId}/users/{userId} \
  --header 'x-app-api-key: <api-key>'

{
  "id": "<string>",
  "username": "<string>",
  "externalId": "<string>",
  "suspended": true,
  "createdAt": "<string>",
  "updatedAt": "<string>",
  "_count": {
    "orders": 123
  },
  "principal": {
    "accounts": [
      {
        "provider": "<string>",
        "email": "<string>",
        "displayName": "<string>"
      }
    ]
  }
}