Task: I need to reach out to customer service on the Booking.com app regarding the availability for non smoking zones in your hotel 
Steps:
open the booking.com app
Go to the profile tab at the bottom right corner of the screen 
Swipe up
Click on the contact customer service option
Click on the contact customer service option
Click on the contact customer service option
Enter a message as  May i know your hotel is smoking free zone 
Click on the send button
Click on the send button