Having virtual cards enabled in Booking.com means you cannot charge the guest until arrival. To disable Virtual Credit Cards follow these steps:

1. Log into the Booking.com extranet.
2. Go to  Property > Policies.

3. Scroll down tot he section Other policies > sub-section Guest payment options.
4. Click the blue button Edit.

5. In the popup scroll to the bottom and change Allow online payments to No.
6. It will ask you why you want to change it,  select Cannot charge virtual cards.
7. Click Save and the pop-up will close.