Please send your application documents by email to danziger_stipendium@uni-heidelberg.de.
If your university diploma is not available by the end of the application period, it is sufficient to submit a provisional certificate from the university confirming your academic performances, so far (ideally with a grade of all examinations, so far), that states that you expect to complete your course of study by the start of the semester following the application period.
Please note that you have to submit your missing certificate by the start of the lecture period.