@Sara1590 I certainly wouldn't send personal information to a third party. It could be a phishing or hacking scam. I suggest you message the host and ask them if they know anything about this, and if they do and say it's some service they use, just tell them you aren't comfortable with providing personal info to that site, that you've already provided the required information for booking to Airbnb.
There is no requirement to do such a thing when booking an Airbnb and if the host insists, I would contact Airbnb and let them know.