Integrating Sage 50 Quantum Accounting 2019 with .NET Application

SUGGESTED

I have built web application (.NET Application) that caters to business needs of my client.

My client have been doing/ managing their accounting via Sage 50 Quantum Accounting Desktop Version software at their end.

Now, since we as a part of their development team has already built an web application, they want us to integrate our custom built web application with Sage 50 Quantum Accounting Desktop.

 Sage 50 Quantum Accounting Desktop: Installed at client end. That is; it is an FAT CLIENT Application, installed on my client's premises SERVER.

Custom .NET based Web Application: This is at my local/ development end.

The solution I read was that I need to use .NET API SDK at any development machine.

Now, when I tried to add a reference to the .NET API in your existing web application, I'm getting below mentioned issues/ errors:

The primary reference "Sage.Peachtree.API, Version=2019.2.0.310, Culture=neutral, PublicKeyToken=d06c16dde04d83e4, processorArchitecture=x86" could not be resolved because it was built against the ".NETFramework,Version=v4.7.1" framework. This is a higher version than the currently targeted framework ".NETFramework,Version=v4.0"

Can you guys tell me where Im going wrong ?

Thanks & have a great day ahead.