Sorry mate but within a few days of the start of each and every month you are posting a question asking where that month's security update is.
It's still March! If it gets to April and you haven't had the March update maybe that justifies a question asking where it is but heck, we are only eleven days into March. Have a little patience.
Experience should be telling you that the Nokia 8 montly security patch updates come around the middle to second half of the month.
March security update just installed in my Nokia 8.