Okay, there is a 50% chance of scam. I have paid an application fee before (in the US), but only at the time I viewed the place. It looks like a reasonable fee is allowed in your state.
At this point, the application fee should only be taken if it is guaranteed that they would rent to you if your credit is acceptable. Which is weird for LL to guarnatee without meeting you. Meanwhile you don't even know yet if you want to rent the place.... do you?
What do you need to have happen to agree to rent the place? Can you do that early so that the landlord can stop listing it?
To check for scammer -- you could ask for a specific type of photo, eg., take a photo from the ad (kitchen?) that was already posted and ask landlord to take a new photo while holding up three fingers, with his face in the photo. Ask for a photo of their drivers license to confirm their name and image against this new photo? Explain about scammers which is the reason for your precautions.
What else can you do? Meet landlord, masked, outside, and check their id and hand over the fee?
You will get crickets if it is a scammer and you ask for any of the above.
I do agree that LL does not want to disturb existing renters, BUT! I just finished finding a rental (early Nov), and everyone (I saw about 9 places) was showing the units in person, they just arranged one day with the tenant having usually stepped out for that time, everyone masked, and hand sanitizer / no touching rule. The agent would wipe down door handles or anything you might have touched. This is a pretty mask-compliant region, too.
So, I guess I am back to scammer. I found a lot of scam ads on Craigslist for rentals.