Create a trip then search using your profile:
To add a railcard manually (as an arranger of travel for other people or it is not loaded in a profile). You can manually enter the railcard details before you search for suitable fares to ensure discounts are displayed.
Underneath the passenger numbers select add railcard. By entering the card details the booking system will only display the appropriate discounted fares for the journey required when the search commences.
Please note that the appropriate rail card must be carried and produced on request with the valid discounted ticket for all rail journeys in either digital or paper form.