Visual studio how to add custom tool/code generator configuration options - visual-studio

Question

I wanted to easily turn some json schema files into classes. So googling I found NJsonSchema and I implemented this in a visual studio custom tool so I can set this on relevant json files and get my classes out. This al works and I pasted the code below. This code comes from this very answer. Though it does need a little updating for VS2022.
I find that documentation on how to do this is rather rare and the thing I am missing is how I can add something like configuration options for the custom tool.
Take for example the line "ClassStyle = CSharpClassStyle.Record," that is something one might want configurable for the user. But I cannot find anything on how to do that. Anyone have a good pointer/answer on this?
Preferably a way to add take the config from some custom properties in the file its properties that are available when the custom tool is configured on a project file.
using System;
using System.Runtime.InteropServices;
using Microsoft.VisualStudio;
using Microsoft.VisualStudio.Shell;
using Microsoft.VisualStudio.Shell.Interop;
using System.Text;
using NJsonSchema.CodeGeneration.CSharp;
using NJsonSchema;
namespace ClassGeneratorForJsonSchema
{
[PackageRegistration(UseManagedResourcesOnly = true)]
[InstalledProductRegistration("GenerateClassesFromJsonSchema", "Use NJsonSchema to generate code from a json schema.", "1.0")]
[Guid("202E7E8B-557E-46CB-8A1D-3024AD68F44A")]
[ComVisible(true)]
[ProvideObject(typeof(ClassGeneratorForJsonSchema))]
[CodeGeneratorRegistration(typeof(ClassGeneratorForJsonSchema), "ClassGeneratorForJsonSchema", "{FAE04EC1-301F-11D3-BF4B-00C04F79EFBC}", GeneratesDesignTimeSource = true)]
public sealed class ClassGeneratorForJsonSchema : IVsSingleFileGenerator
{
#region IVsSingleFileGenerator Members
public int DefaultExtension(out string pbstrDefaultExtension)
{
pbstrDefaultExtension = ".cs";
return pbstrDefaultExtension.Length;
}
public int Generate(string wszInputFilePath, string bstrInputFileContents,
string wszDefaultNamespace, IntPtr[] rgbOutputFileContents,
out uint pcbOutput, IVsGeneratorProgress pGenerateProgress)
{
try
{
var schema = JsonSchema.FromJsonAsync(bstrInputFileContents).Result;
var generator = new CSharpGenerator(schema, new CSharpGeneratorSettings()
{
JsonLibrary = CSharpJsonLibrary.SystemTextJson,
ClassStyle = CSharpClassStyle.Record,
Namespace = wszDefaultNamespace
});
byte[] bytes = Encoding.UTF8.GetBytes(generator.GenerateFile());
int length = bytes.Length;
rgbOutputFileContents[0] = Marshal.AllocCoTaskMem(length);
Marshal.Copy(bytes, 0, rgbOutputFileContents[0], length);
pcbOutput = (uint)length;
}
catch (Exception ex)
{
pcbOutput = 0;
}
return VSConstants.S_OK;
}
#endregion
}
}