string path7z = $"7zsource\\{project.name}";
string path7zip = $"7z\\{project.name}.7z";

ProcessStartInfo p = new ProcessStartInfo
{
   FileName = "7za.exe",
   Arguments = "a -t7z \"" + path7zip + "\" \"" + $".\\{path7z}\\" + "\" -mx=9",
   WindowStyle = ProcessWindowStyle.Hidden
};
Process x = Process.Start(p);