Probably, the only difference would be your authentication into the server before save any file.
The easiest way to do that, would be using "User Impersonation".
Install it in your application
https://www.nuget.org/packages/UserImpersonation/
Install-Package UserImpersonation -Version 1.0.0
A Quick example with "User Impersonation DLL"
using (UserImpersonation obj = new UserImpersonation("YourUserNameToAccessTheServer", "YourDomain", "UserPassword"))
{
string YourDirectoryFullNameExample = "\\ServerName\\Folder1\\Folder2\\File.Pdf"
if (File.Exists(YourDirectoryFullNameExample))
{
MessageBox.Show("xx.", "xx");
}
else
{
Directory.CreateDirectory(@"YourDirectoryFullNameExample);
PdfWriter.GetInstance(pdfDosya, new FileStream(YourDirectoryFullNameExample, FileMode.Create));
}
}