ManagedPlugin.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>netstandard2.0</TargetFramework>
    <LangVersion>preview</LangVersion>
    <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
    <NullableReferenceTypes>True</NullableReferenceTypes>
  </PropertyGroup>

  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
    <DefineConstants>TRACE</DefineConstants>
  </PropertyGroup>
  <ItemGroup>
    <Reference Include="UnityEngine.CoreModule">
      <HintPath>C:/Program Files/Unity/Hub/Editor/2018.4.4f1/Editor/Data/Managed/UnityEngine/UnityEngine.CoreModule.dll</HintPath>
    </Reference>
  </ItemGroup>
</Project>