@Robert ******
, my experience is that a 60 day extension - one only, or two, I forget - is available on the spot right up to the date of expiry of permission to stay. But that an application for a one year extension is required before 14 days before expiry of permission to stay.
I'm unclear whether the 60 day extension would reset the process of applying for that type of Visa, though......... That could require a trip out of country, on pre-COVID rules.........