var provider = new XlsxFormatProvider();
using (var fs = File.OpenRead("image.xlsx"))
{
    var workbook = provider.Import(fs);
    Assert.AreEqual(workbook.ActiveWorksheet.Shapes.Images.Count(), 1);
}

 private async Task GenererOperations()
        {
            RadFlowDocument document = new RadFlowDocument(); ;
            RadFlowDocument documentFinal = new RadFlowDocument();
            var docxProvider = new DocxFormatProvider();



            foreach (OperationAffecteeViewModel operationAffectee in OperationsAffectees)
            {
                using (Stream input = File.OpenRead("Modele.docx"))
                {
                    document = docxProvider.Import(input);
                }
                RadFlowDocumentEditor editor = new RadFlowDocumentEditor(document);
                GoToBookmark(document, editor, "OUVRAGE");
                editor.InsertText(operationAffectee.LibelleOuvrage);
                GoToBookmark(document, editor, "OPERATION");
                editor.InsertText(operationAffectee.LibelleTypeOperation);
                GoToBookmark(document, editor, "DATE_PRÉVUE");
                editor.InsertText(operationAffectee.DatePrevisionnelle.Date.ToString("dd/MM/yyyy"));

            }

            //chargement de la police pour éviter de perdre les caractères spéciaux lors de l'exportation
            var fontData = File.ReadAllBytes(@"wwwroot/fonts/Calibri_Regular.ttf");
            FontsRepository.RegisterFont(new Telerik.Documents.Core.Fonts.FontFamily("Calibri"), FontStyles.Normal, FontWeights.Normal, fontData);

            var providerPdf = new PdfFormatProvider();
            using (Stream outStream = File.OpenWrite("sample.pdf"))
            {
                providerPdf.Export(document, outStream);
            }

            await InvokeAsync(() => this.StateHasChanged());
        }

        
        private void GoToBookmark(RadFlowDocument document, RadFlowDocumentEditor editor, string bookmarkName)
        {
            var bookmark = document.EnumerateChildrenOfType<BookmarkRangeEnd>().FirstOrDefault(rangeStart => rangeStart.Bookmark.Name == bookmarkName);
            if (bookmark != null)
            {
                editor.MoveToInlineEnd(bookmark.Paragraph.Inlines[0]);
            }
        }

run.FontWieght = FontWieghts.Bold;

public byte[] Convert()
{
    //to support fonts
    Telerik.Windows.Documents.Extensibility.FontsProviderBase fontsProvider = new FontsProvider();
    Telerik.Windows.Documents.Extensibility.FixedExtensibilityManager.FontsProvider = fontsProvider;

    //to support PNG's
    Telerik.Windows.Documents.Extensibility.JpegImageConverterBase jpegImageConverter = new Telerik.Documents.ImageUtils.JpegImageConverter();
    Telerik.Windows.Documents.Extensibility.FixedExtensibilityManager.JpegImageConverter = jpegImageConverter;

    var importProvider = new DocxFormatProvider();
    byte[] templateData = GetTemplateData(); 
    var template = importProvider.Import(templateData);

    var pdfProvider = new PdfFormatProvider();
    PdfExportSettings settings = new();
    settings.ComplianceLevel = PdfComplianceLevel.PdfA3U;
    pdfProvider.ExportSettings = settings;
    var pdfBytes = pdfProvider.Export(template);
    return pdfBytes;
}

//... end class

public class FontsProvider : Telerik.Windows.Documents.Extensibility.FontsProviderBase
    {
        public override byte[] GetFontData(FontProperties fontProperties)
        {
            string fontFileName = fontProperties.FontFamilyName + ".ttf";
            string fontFolder = Environment.GetFolderPath(Environment.SpecialFolder.Fonts);
            string targetPath = Path.Combine(fontFolder, fontFileName);

            DirectoryInfo directory = new DirectoryInfo(fontFolder);
            FileInfo[] fontFiles = directory.GetFiles("*.ttf");
            if (fontFiles.Any(s => s.Name.Equals(fontFileName, StringComparison.InvariantCultureIgnoreCase)))
            {
                using (FileStream fileStream = File.OpenRead(targetPath))
                {
                    using (MemoryStream memoryStream = new MemoryStream())
                    {
                        fileStream.CopyTo(memoryStream);
                        return memoryStream.ToArray();
                    }
                }
            }

            return null;
        }
    }

                var provider = new PdfFormatProvider();
                var document = provider.Import(File.ReadAllBytes(dokument.Hyperlink));