Booking.com Did Not Clearly Disclose Caesars Palace Mandatory Fee

I booked a deluxe room at Caesars Palace Las Vegas through Booking.com for a one‑night stay from 4 June to 5 June. During my stay, the hotel charged an additional mandatory fee of 90 USD on 5 June, which I had not been clearly informed about at the time of booking. This unexpected extra cost was not presented transparently on Booking.com, and I only became aware of it when it was charged at the hotel. I have not yet contacted Booking.com or Caesars Palace customer service about this issue, but I am now submitting this complaint because I consider this charge to be unfair and misleading. I kindly request a full refund of the additional 90 USD that was charged as a mandatory fee on 5 June, or another appropriate resolution. I would like this matter to be reviewed and handled as soon as possible.