Normally when you click Edit in a booking you will see an option to manually add booking protect:

However, if you don't see this option you need to ensure your booking passes this criteria:

1. Cannot be added to bookings more than 13 months in the future

2. If number of adults is 0

3. If Total rent = £0

4. Is only available on up to £1500 per person e.g. you would not be able to add Booking Protect if you had a booking for two that exceeded £3000.

No, this option is not available. Booking Protect can only be added before the final balance has been paid on any booking.

No,  the cover doesn't move automatically.  You would also need to make this change in your Booking Protect account directly. 

Booking Protect will not provide a refund where guests are prevented from travelling to the holiday due to an outbreak of a contagious disease and the Government or any agency acting on behalf of the Government has imposed a ban on travel.