I often need to call external command line programs from within my C# code.  To do this, I use a Process object.  Here is some example code I use for calling a Python program:

private void Execute()
{
    Process proc = new Process();
    
    proc.StartInfo.WorkingDirectory = @"C:\scripts";
    proc.StartInfo.FileName = "python.exe";
    proc.StartInfo.Arguments = "foo.py";
    proc.StartInfo.UseShellExecute = false;
    proc.StartInfo.RedirectStandardOutput = false;
    proc.StartInfo.RedirectStandardError = true;
    proc.Start();
    proc.WaitForExit();
    proc.Close()
}