I do not recognize the code you provided.
I think maybe your development team might develop a wrapper for our APIs?
Anyway, if you are looking for real-time streaming data.
I think you may refer to Real-Time SDK (RTSDK) and use the Enterprise Message API(EMA) in the SDK package.
You can find some information here, https://developers.refinitiv.com/en/api-catalog/elektron/elektron-sdk-java/
I highly suggest that you contact your Refinitiv Account Manager, so they can help to understand your requirement, your current product and suggest a suitable solution to your company.
Do you know the product name to which your .NET app connects to?
So I can try to give you some suggestions regarding the product you are currently using.
Eikon Data API is an API that connects to Eikon Desktop application on Windows.
It only supports Python.
I think this is no what you are looking for.I would suggest that you contact with Refinitiv Account Manager who manages your account so they can bring in relevant colleagues to provide you more information.