From the amazing mind of Satan's Maggoty Cum Fart.

IIRC, the invitation needs to be made by a resident, not a proxy —and from inside said building, I believe. That said, my basis for this is decades of "research" spanning innumerable literary works (including, but not limited to comic books, classics, cryptid reports, etc.), RPG setting source tomes, and scores of other media, from antiquated to modern. I guess I'll find out the hard way? 😋

In Renfield the vampire enters an apartment because there's a welcome mat