Hello there, it's me again. :)
In addition to the question above, can I also wait couple weeks or a month to add my pass to the Rail Planner application?
For example;
Ticket Purchase: 10/05/2022
Adding to App: 25/06/2022
Activation/begging of trip: 07/20/2022
Is it possible? Do I have to add the ticket to my app right away?
You need to activate the pass on the phone that you will use on your trip.
You can't move the pass from one device to another without help from the Interral/Eurail customer support.
But for the ORDER you do not yet have the fone-nr (I just tried)-you mention that when you do the activation=when you have decided on the actual start day. You do NOT need to do that for making advance REServations. You have to create account on @mail or use the fb or Gmail accounts you may have