Admob Rewarded video "setUserId" API

Admob Rewarded video "setUserId" API
0

I would like to setUserId

https://developers.google.com/android/reference/com/google/android/gms/ads/reward/RewardedVideoAd#setUserId(java.lang.String)

via cpp api because I would like to use SSV (server-side verification).

Is it possible via SDKBOX ?
Thanks

sorry, but not support this api yet.