To allow the ‘Refundable Bookings’ banner in the front-end booking steps, go to Settings > Integrations > Refund Protect
Once in this page:
Enable Refundable Booking >>> Yes
Optional Vs Mandatory
The second option in the above screenshot gives you the possibility to make the Refundable Booking as a mandatory option (If Yes is selected). On the other hand, if you select No, the guest has the option to either opt-in or opt-out for the booking protection.
Banner if mandatory
Banner if optional