CreateMutex

[DllImport("Kernel32.dll", SetLastError = true)][return: MarshalAs(UnmanagedType.SafeHandle)]
public static extern SafeWaitHandle CreateMutex(
   IntPtr lpMutexAttributes,
   [MarshalAs(UnmanagedType.Bool)] bool bInitialOwner,
   string lpName
);

Microsoft documentation: Link