Requirement for the cancellation of train journeys:
The booker has the team booking right for the traveller.
At "travel management" -> "team booking" it is possible to select the person for whom you would like to cancel. In the selection, only those persons are shown who are authorized to book or cancel.
Once a person has been selected, the name of the traveller changes in the login area. Then go to "my data" -> "DB booking search".
Now click on the pencil under "edit" to cancel the trip.