Power steering rack

[DVR V8]

Hi. I had the hydraulic rack on the Griff rebuilt a couple of years ago but only just noticed that they didn't refit the gease nipple on the right hand side. I just have a 6mm threaded hole. Does that mean it's not used or do you still need to put some red grease in periodically? All I've ever done over 22 years is change the red fluid every 2 years. Regards.