Finding and replacing text with content in ASP.NET Core Word

using Syncfusion.DocIO;
using Syncfusion.DocIO.DLS;

using (FileStream inputStream= new FileStream(Path.GetFullPath(@"../../../Data/Input.docx"), FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
   //Load an existing Word document.
   using (WordDocument document = new WordDocument(inputStream, FormatType.Docx))
   {
       //Create a BlockContentControl.
       BlockContentControl blockContentControl = new BlockContentControl(document, ContentControlType.RichText);
       //Add a new table to the block content control.
       WTable table = blockContentControl.TextBody.AddTable() as WTable;
       //Specify the total number of rows and columns.
       table.ResetCells(1, 2);
       //Get first row of the table.
       WTableRow row = table.Rows[0];
       //Add a new paragraph to the first cell of the table.
       IWParagraph cellParagraph= row.Cells[0].AddParagraph();
       row.Cells[0].CellFormat.VerticalAlignment = VerticalAlignment.Top;
       FileStream imageStream = new FileStream(Path.GetFullPath(@"../../../Data/image.png"), FileMode.Open, FileAccess.ReadWrite);
       //Append a picture to the cell.
       WPicture picture = cellParagraph.AppendPicture(imageStream) as WPicture;
       picture.Height = 88.3f;
       picture.Width = 142.2f;
       //Add a new paragraph to the next cell.
       cellParagraph = row.Cells[1].AddParagraph();
       row.Cells[1].CellFormat.VerticalAlignment = VerticalAlignment.Top;
       cellParagraph.ParagraphFormat.BeforeSpacing = 12f;
       //Append text to the cell.
       IWTextRange text = cellParagraph.AppendText("Mountain-200");
       cellParagraph.ParagraphFormat.AfterSpacing = 3f;
       //Set the text format.
       text.CharacterFormat.Bold = true;
       text.CharacterFormat.FontName = "Arial";
       text.CharacterFormat.FontSize = 16f;
       //Add a new paragraph.
       cellParagraph = row.Cells[1].AddParagraph();
       //Append text to the paragraph of a cell.
       cellParagraph.AppendText("Product No: BK-M68B-38 \nSize: 38\nWeight: 25\nPrice: $2,294.99\n\n ");
       //Specify the table borders border type.
       table.TableFormat.Borders.BorderType = BorderStyle.Single;
       //Create a textbody part object.
       TextBodyPart textBodyPart = new TextBodyPart(document);
       //Add the block content control to the textbodyPart.
       textBodyPart.BodyItems.Add(blockContentControl);
       //Replace all entries of a given regular expression with the text body part.
       document.Replace(new Regex("<<(.*)>>"), textBodyPart);
       //Create a file stream.
       using (FileStream outputFileStream = new FileStream(Path.GetFullPath(@"../../../Sample.docx"), FileMode.Create, FileAccess.ReadWrite))
       {
           //Save the Word document to the file stream.
           document.Save(outputFileStream, FormatType.Docx);
       }
   }
}