in the older versions of the Unreal Plugin we were able to set the SEDataRequest PropertyName via Code. Now that i have moved to the latest version of the Plugin the Function is protected Is there a different approach to creating a request from Code ?
You should be creating data requests via the data request manager associated with the engine you are using.
https://gitlab.kitware.com/physiology/engine/-/blob/stable/src/cpp/howto/HowTo-EngineUse.cpp?ref_type=heads#L162
Since you are in C++, you can just access data directly via the C++ API, but if you want to use a data request, then you can set that up in something like this ReadyData method and create your own DataReqest BluePrint object (like this) you can translate into the CreateDataRequest method in that ReadyData method