i thought the f108 has no nipple? This is the one I linked. https://www.amazon.com/gp/product/B07D99Q2B9/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&psc=1

nice. which one did you get? according to the site this should fit on the frs. https://www.amazon.com/gp/product/B07D99Q2B9/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&psc=1

Who needs a drain plug?

You're just confused by the nomenclature. It's M16-1.5, which is a metric 16mm bolt with a thread-pitch of 1.5mm. Regardless, the Fumoto F-108 is the standard drain valve that fits your car. If you want to attach a hose to the end of the valve, get the F-108S or F-108N.