@Shala15
Probably legit. I don't know why you need it for a PCR test, but it's possible, I suppose. I know guests need the address of the accommodation to properly fill out covid entry paperwork for Spain, but many just write the name of the accommodation and that seems to work.
Otherwise, except in these rare cases, I only give them the exact location the day before their arrival. They can look it up anytime they want on Airbnb once they're booked, but most don't bother.
I send it the day before arrival not only because it's far less likely to get "lost in the noise of daily life", but a lot can happen between booking it and arrival.