Question IronSource.Agent.setUserId() not working for s2s callback

Hello,

I'm trying to implement s2s callback.
The documentation said to IronSource.Agent.setUserId() before the init request.
However, my users will have an userid AFTER they login, which is after initialization is called.
Right now I'm using IronSource.Agent.setUserId(myuserid) right after users login within my app.
However, s2s callback received on my server shows userid=0.

How to make sure IronSource.Agent.setUserId() sends unique userid after login?

Thanks in advance.

 

@cnguyen_unitylevelplay @yunanhou any help would be greatly appreciated...

 

I'm attempting to pass the device ID using custom parameters. When I tried it mediation stops working (no ads loaded). Any help is appreciated.
Here's my code before initialization:

Dictionary<string, string> rvParams = new Dictionary<string, string>();
rvParams.Add("device", SystemInfo.deviceUniqueIdentifier);
IronSource.Agent.clearRewardedVideoServerParams();
IronSource.Agent.setRewardedVideoServerParams(rvParams);