✅ C# Bold Text

I'm trying to make Address: Bold, but I'm having issues with it and it's displaying <b> </b> as text.
This is in WinUI 3

        private void locInfo_Click(object sender, RoutedEventArgs e)
        {
            var selectedItem = (Location)MainList.SelectedItem;
            if (selectedItem != null)
            {
                DialogHelper dialogHelper = new DialogHelper();

                var Title = "Location Information";
                var Address = string.Format("<b>Address:</b> {0}", selectedItem.LocationInformation.AddressInfo.FullAddress);
                var Phone = string.Format("Phone: {0}", selectedItem.LocationInformation.PhoneNumber);
                var Fax = string.Format("Fax: {0}", selectedItem.LocationInformation.FaxNumber);
                var Content = string.Format("{0}\n\n{1}\n{2}", Address, Phone, Fax);

                dialogHelper.DisplayDialog(Title, Content, "Ok");
            }
        }

That's because <b> is HTML

got it ok, will update with a textblock