NuGet.config

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <!-- NOTE: Leave this file here and keep it in sync with list in dir.props. -->
  <!-- The command-line doesn't need it, but the IDE does.                    -->
  <packageSources>
    <clear/>
    <add key="myget.org dotnet-core" value="https://dotnet.myget.org/F/dotnet-core/api/v3/index.json" />
    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
  </packageSources>
</configuration>

Program.cs

using System;
using System.Reflection.Emit;
using System.Globalization;
using System.Reflection;

namespace testNca
{
    class Program
    {
        static void Main(string[] args)
        {
            Type[] mathArgs = { typeof(double), typeof(double) };

            var powerOf = new DynamicMethod("PowerOf",
                typeof(double),
                mathArgs,
                typeof(double).Module);

            ILGenerator il = powerOf.GetILGenerator(256);
            il.Emit(OpCodes.Ldarg_0);
            il.Emit(OpCodes.Ldarg_1);
            il.Emit(OpCodes.Call, typeof(Math).GetMethod("Pow"));
            il.Emit(OpCodes.Ret);
            
            powerOf.DefineParameter(1, ParameterAttributes.In, "base");
            powerOf.DefineParameter(2, ParameterAttributes.Out, "exponent");
            
            object[] invokeArgs = { 2, 5 };
            object objRet = powerOf.Invoke(null, BindingFlags.ExactBinding, null, invokeArgs, new CultureInfo("en-us"));

            ParameterInfo[] parameters = powerOf.GetParameters();
        }
    }
}

testNca3.0.csproj

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

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp3.0</TargetFramework>
    <RootNamespace>testNca3</RootNamespace>
    <NETCoreAppMaximumVersion>3.0</NETCoreAppMaximumVersion>
    <RuntimeFrameworkVersion>3.0.0-preview1-26912-03</RuntimeFrameworkVersion>
  </PropertyGroup>
</Project>