Windows Container - Text - Error

[a09308060]

I use Windows Container Creat PDF

I have Use
FontManager.RegisterFontWithCustomName("SourceSerif4", File.OpenRead("PDFFont/SourceSerif4-Italic-VariableFont_opsz,wght.ttf"));

column.Item().Row(row =>
{
row.RelativeItem().PaddingBottom(10).AlignCenter().Text("☐").FontFamily("SourceSerif4").FontSize(19).ExtraBlack();
});

Have Error:

System.ArgumentException: 'The typeface 'SourceSerif4' could not be found. Please consider the following options: 1) install the font on your operating system or execution environment. 2) load a font file specifically for QuestPDF usage via the QuestPDF.Drawing.FontManager.RegisterFontType(Stream fileContentStream) static method. Available font family names: []'