Would have been more helpful to tell us WHERE you are now.

In UK the railways do not deal with that since very long time. there are in UK some private companies who can offer old style paper passes and probably send it regisetred to UK-adresses in a few days. And DO also note that €* to go to mainland is full for coming weeks-plus there are strikes threatening

(ffestiniog travel springs in my mind, check seat61.com for more advice)

In SE - SJ will also not do it anymore

BUT in DK DSB does (only a few main stations) and DB-Germany, SBB-Swiss and OeBB-Austria about anywhere.

OR bite the bullet buy new fone and set SIM card with old nr in.

About refunds I really cannot say-except it will take a very long time.

Thank you very much for replying! Since it was hard for me to get in contact with the interrail company and when calling the national rail they said that it is not possible to print a pass on the station, I decided it was best to not take any risks and buy new tickets from trainline instead (much more expensive though). I applied for a refund, but it seems to be only 85% which is a bit disappointing since the problem was not really my fault.

Well… they do give the minimum requirements for the rail planner app. Does your phone meet those requirements?

Unfortunately I thought I would be able to download the pass since I had the app installed

But does your phone meet the requirements for the app? If yes, then you should ask for a solution or a full refund.