code for bar-code scanner for Rasberry Pi 3 not working on Windows 10 for IoT

I am trying to help my little sister with a project she is stuck on. She is trying to get a bar-code scanner to work with a Raspberry Pi 3 (scanner connected via Ethernet). She has found and worked on a piece of code (attached) that works no problem on Windows 10 on her laptop, but it will not work on the Raspberry Pi running Windows 10 IoT Core. The code is written in C# on Visual Studio. When opened on Visual Studio on the Raspberry, the code looks like it doesn’t recognize all the functions that it does on the laptop, and it obviously doesn’t work.
Any ideas? What to try? What would you recommend for the next steps?

PS: my apologies for the probable lack of useful information and misuse of terminology as I am not familiar at all with any of this. But I really would like to help my sister who is pulling her hair out right now. She is not as comfortable in English as I am, so I figured I would try to post in English and hope that someone can figure out how to get her going with this.
Thank you.

She has spent a lot of time (and frustration) on this and she is a very experienced industrial programmer so I know she tried quite a few things already but I don’t know exactly what. I don’t have enough expertise myself to know what to ask her and what is important/interesting to share with you. But let me know if you have any specific question and I will definitively relay the questions and answers.