Sandbox.csproj

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

  <PropertyGroup>
    <TargetFramework>netcoreapp3.1</TargetFramework>
    <IsPackable>false</IsPackable>
    <WarnOnPackingNonPackableProject>false</WarnOnPackingNonPackableProject>
  </PropertyGroup>

  <ItemGroup>
    <Protobuf Include="greet.proto" GrpcServices="Server" />
    <Protobuf Include="httpapi.proto" GrpcServices="Server" />

    <PackageReference Include="Grpc.Tools" Version="$(GrpcCorePackageVersion)" />
    <PackageReference Include="Grpc.AspNetCore.Server" Version="$(GrpcAspNetCoreServerPackageVersion)" />
  </ItemGroup>

  <ItemGroup>
    <ProjectReference Include="..\..\..\src\Microsoft.AspNetCore.Grpc.HttpApi\Microsoft.AspNetCore.Grpc.HttpApi.csproj" />
    <ProjectReference Include="..\..\..\src\Microsoft.AspNetCore.Grpc.Swagger\Microsoft.AspNetCore.Grpc.Swagger.csproj" />
  </ItemGroup>

</Project>