Installing External .NET Library in Creatio Custom Package

Problem Description
I'm trying to integrate an external .NET library (Npgsql) into my custom Creatio package to connect with a PostgreSQL database. However, I'm encountering version compatibility issues with System.Runtime.

 Current Setup
- Package Name: UsrWebServiceLog
- Target Library: Npgsql
- Current Error:
 

Assembly 'Npgsql' with identity 'Npgsql, Version=8.0.5.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7' uses 'System.Runtime, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' which has a higher version than referenced assembly 'System.Runtime'

 What I've Tried
1. Adding the library reference directly to my package project
2. Attempting to use an older version of the library
3. Adding System.Runtime reference

 Questions
1. What is the correct approach to include external .NET libraries in a Creatio custom package?
2. Are there specific version requirements or limitations I should be aware of?
3. Should the library be installed at the workspace level or package level?
4. Is there a specific location where external DLLs should be placed?

 Code Context
I'm trying to implement a web service that connects to PostgreSQL:

namespace Terrasoft.Configuration.UsrPostgressConnection
{
   [ServiceContract]
   public class UsrPostgressConnection : BaseService
   {
       // Service implementation
   }
}

Any guidance on best practices for managing external .NET dependencies in Creatio would be greatly appreciated. Thank you in advance!

 Environment Details
- Creatio Version: 8.1.3
- Development Environment: On-site
- .NET Framework Version: 4.7.2