Auto-replenishment is a default function that cannot be deactivated.
However, you can disable the 'Reopen closed rooms' setting upon request. This is the setting where cancelled rooms go back on sale regardless of whether the property has closed availability for that date.
We recommend asking property partners to contact their local Booking.com support team if they want to deactivate this option.
For more information about how auto-replenishment works, have a look at our introduction to the topic.