If you are planning to do a professional internship, then sign up for the Moodle course 

https://moodle.uni-ulm.de/course/view.php?id=6001  

There you will find an explanation of the individual steps and which documents and information are required.

You do not have to register for the "Professional internship" examination in the university services portal. The chairman of the examination board will arrange for the entry of this examination performance when all parts (confirmation of the company, report, presentation) have been completed.

There is a list of companies list of companies where students have already completed a professional internship.