platform property
Platform is the ad network: meta, google, tiktok or x, and nothing else — a write naming another is 400. Empty stores as meta. Only meta executes today; launching any of the other three is 501.
Please note: This property should have been non-nullable! Since the specification file does not include a default value (using the "default:" property), however, the generated source code must fall back to having a nullable type. Consider adding a "default:" property in the specification file to hide this note.
Implementation
String? platform;