Is there a way to verify if the Rewarded Video Ad was watched by client (OnAdRewarded) on a server? Is there any integration I can use with Google Cloud Functions?
I thought it's possible to verify a token sent by client to the server with admob admin SDK but it seems that it's not possible and we can only verify the ad on the client.
It is now possible with Server-Side Verification (SSV) Callbacks.
Server-side verification callbacks are URL requests, with query parameters expanded by Google, that are sent by Google to an external system to notify it that a user should be rewarded for interacting with a rewarded video ad. Rewarded video SSV (server-side verification) callbacks provide an extra layer of protection against spoofing of client-side callbacks to reward users.