how to delete the object I am renting with Booking.com, because it is no longer in function

Hi Enes,

If you would like to terminate your contract with Booking.com, the instructions are in the link below.

https://partner.booking.com/en-gb/help/legal-security/policies-local-laws/how-can-i-remove-property-or-end-my-partnership-bookingcom

If you'd like to speak with us regarding this, you'll find the phone number in your extranet. 

Click on Inbox > Booking.com Messages > Contact Us. 

Kind regards,

C.Chin