How do i enter the exact train i have seat reservations on to my eurail mobile pass?

Hello everyone, 

I am travelling to the UK for the first time and also making use of the eurail global mobile pass for the first time and would like to know how to add the exact train that I have booked seat reservation on, to my trips in my mobile pass. From what I can see, the mobile pass only shows you timings of the trains between two places and there is no information such as train number etc. written anywhere on the railplanner app. I have booked my seat reservation from Edinburgh to London on LNER website by matching the timetable on the rail planner app to that of the LNER website. How do I ensure that my seat reservations are on the exact train that I have added to my pass?