the following quick and dirty script is provided "as-is" with no support, further development or security affirmations. Only use it if you know what it does.
- login to CampusDual
- view calendar
- press F12 to show developer console
- switch to "Network"
- find your calendar-json request url
- write a python script to export data into calendar app readable .csv
if __name__ == '__main__':
export_to_csv("./test.csv", "https://selfservice.campus-dual.de/room/json?userid=[YOUR_USER_ID]&hash=[MAGIC_HASH]&start=[TIME_STAMP_START]&end=[TIME_STAMP_END]")