Openmutex

[DllImport("Kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)][return: MarshalAs(UnmanagedType.SysInt)]
public static extern IntPtr OpenMutex(uint dwDesiredAccess,
   [MarshalAs(UnmanagedType.Bool)] bool bInheritHandle,
   string lpName
);

Microsoft documentation: Link