issues with code generator

[Generator(LanguageNames.CSharp)]
public class TestGenerator : IIncrementalGenerator {
    void IIncrementalGenerator.Initialize(
        IncrementalGeneratorInitializationContext context) {
        context.RegisterSourceOutput(context.AnalyzerConfigOptionsProvider, (x, options) => {
                x.AddSource(
                    "_.g.cs",
                    SourceText.From("/* hello */", Encoding.UTF8)
                );
            }
        );
    }
}

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

    <PropertyGroup>
        <TargetFramework>netstandard2.0</TargetFramework>
        <LangVersion>Latest</LangVersion>
        <Nullable>enable</Nullable>
        <EnforceExtendedAnalyzerRules>true</EnforceExtendedAnalyzerRules>
        <DevelopmentDependency>true</DevelopmentDependency>
    </PropertyGroup>

    <ItemGroup>
        <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.12.0" PrivateAssets="all"/>
        <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.11.0" PrivateAssets="all"/>
    </ItemGroup>

    <ItemGroup>
        <None Include="$(OutputPath)\$(AssemblyName).dll" Pack="true" PackagePath="analyzers/dotnet/cs" Visible="false"/>
    </ItemGroup>

</Project>