NuGet:

• https://nuget.org/packages/kenjiuno.PdfSharp.Xps
• https://nuget.org/packages/kenjiuno.PdfSharp-WPF

  Install-Package kenjiuno.PdfSharp.Xps

XPS to PDF in WPF application:

  PdfSharp.Xps.XpsConverter.Convert(fpXps);

Docs: https://hiraokahypertools.github.io/PDFsharp/