Train Reservation

Hi there! 

So I’m in Barcelona right now and yesterday I went to the train station to get a seat reservation to Bordeaux St Jean and they told me I could only get one for the transit train to Nerbonne, wich I did and the seat reservation from Narbonne to Bordeaux I should get when I’m in France or online. But when I was trying to get it online It asks me for a “Interrail cover number” but the thing is I have the mobile pass and not the paper format. 

I won´t be in france until exactly the day of my journey, and the missing seat reservation is for the train I would need…. so it would be really risky to wait until minutes before departure to go in person to the service at the station and ask for buying the seat reservation. That is really risky. If that doesn´t work, I lost the following connections for what I already have reservations.

Could somebody with experience on this help me, please? I cannot believe that this risky way is really the only way…

Thanks a lot in advance!

Cheers,

Tim.