Oof, not in the UK. (At least not with Prime.)
Perhaps not quite as easy (for small enough items) as when I mostly commuted, and could print a label and leave it in an outgoing mail pile, but certainly from home I way prefer that than going to a post office (even in the absence of coronavirus restrictions).
I actually bought a printer for that purpose. A direct thermal label printer, because that's all I needed it for (and it was cheaper, has no ink to run out/dry out during a period of no use, etc.).