can Listing be private and only be accessible with the direct link ?
Yes, according to https://community.withairbnb.com/t5/Hosting/private-listing/td-p/8585:
If you dont' want the general public to see your listing, yes, you can "hide" it by either unlisting or snoozing it (go to manage listing, then click on menu bar on right side, and in the dropdown menu at the bottom you will see a box that says "listed/snoozed/unlisted". )
When a listing is "snoozed" (for certain dates) or "unlisted" then the public cannot see it. IF you wanted someone to book it, you would need to "list" it again just long enough for them to book it, and then as soon as they book it, snooze or unlist it again. The person who books would still be able to see the listing but the general public would not
Each listing has a unique web address, this web address can be typed into any browser and your listing will pop up even when its snoozed, although as far as I'm aware it can't be booked.