updateServerSideVerification method

@override Future<void> updateServerSideVerification(ServerSideVerification ssv)

Applies (or replaces) server-side verification options on this already-loaded ad — call any time before show().

Real apps set the SSV userId after login and per-show customData (which mission/level earned the reward), long after the ad preloaded (2026-07 audit). Throws an AdFlowError on failure — a caller granting high-value rewards must know its verification payload did not attach.

Implementation

@override
Future<void> updateServerSideVerification(ServerSideVerification ssv) async {
  final error = ssvUpdateError;
  if (error != null) throw error;
  ssvUpdates.add(ssv);
}