You can travel on 2 days (00.00-23.59 CET) in your home country. During that time you can take several trains. 

If you have an IPhone you should not add manual journeys as there is a bug that can make journeys dissappear. 

What route is missing from the app?

Oh I do have an iPhone. I want to go from Copenhagen to Munich via Hamburg. The train leaves at 17:18. any other option I have? 

On what date? 

Are you currently travelling?

On Saturday actually. I have to return early due to an injury. 

Ok  

I know that there are problems with the trains from Copenhagen to Hamburg in the app. 

I suggest that you don't add the journey now. Wait until just before boarding the train on Saturday. First make sure that you have an internet connection so that the latest timetable can be downloaded to your phone and then hopefully the app will be updated with the train leaving Copenhagen at 17.18.

Otherwise I guess that you have to enter the journey manually and hope that it works. 

I hope that you have a reservation for the train from Copenhagen as they are mandatory during the summer.

Hm ok that does not sound very stable. What if it is not working? 
Reservation I will make once I know I can use the train. Already on my to-do list

thanks for your help! 

Ok. The direkt trains between Denmark and Germany are fully booked for weeks so you need to have a plan B if you don't have a reservation. 

I checked there are seats available. Only question is if Trip cannot be added…

How far in the reservation process did you go when you checked if seats are available?

I just checked at 

https://travel.b-europe.com/dsb-rail/en/reservation-only?&_ga=2.110710661.1823193415.1657781565-2080903824.1657781565#TravelWish

There are no seats available on the 17.18 train.

Thanks. Was just in the phone now with some agent. We found a connection. Thanks for your help.