How can I get POA notarized during stay home order?

Banks, government centers and hospitals all have notaries on staff all (or most of) the time. Call to see if they are available to do what you need.

Call local notaries. There are laws in effect now in most states where notaries can witness signature some other way than going there in person. Ask them for advice.
There are also visiting notaries. Would have to stay away/distance and not share pens. Check in your local area. and Good luck.