First, add the following packages to your project. Tapper.Analyzer is optional, but recommended.
dotnet add package Tapper.Attributes
dotnet add package Tapper.Analyzer (optional, but recommended.)
Next, apply the [TranspilationSource] Attribute to the C# type definition.
using Tapper;
namespace SampleNamespace;
[TranspilationSource] // <- Add attribute!
public class SampleType
{
public List<int>? List { get; }
public int Value { get; }
public Guid Id { get; }
public DateTime DateTime { get; }
}