Custom URL links

{
  "projectId": "proj_123",
  "name": "Campaign landing page",
  "publicName": "View the campaign",
  "retailer": "custom",
  "intent": "custom_url",
  "customUrl": "https://www.example.com/landing-page",
  "fallbackUrl": "https://www.example.com/",
  "tracking": {
    "utm": {
      "source": "social",
      "medium": "instagram",
      "campaign": "summer-launch"
    },
    "tags": ["campaign", "social"]
  },
  "metadata": {
    "campaignId": "cmp_456"
  }
}