What are the alternatives to passing the integration course for the permanent residency application?

I was checking the [requirements](https://service.berlin.de/dienstleistung/121864/standort/121885/) for the permanent residency application and noticed it says one needs to provide the certificates of approval from the German integration courses. However, after that, it says the following:

\>Die Bescheinigungen erleichtern die Prüfung des Antrags. Sie können bei Vorsprache Ihre ausreichenden Deutschkenntnisse sowie Grundkenntnisse der Rechts- und Gesellschaftsordnung aber auch anders nachweisen.

But no further info is provided. So what are these alternative ways to prove knowledge?

I live in Berlin and it’s almost impossible to find spots for integration courses, especially at my level of German (these courses are given in priority to people with < B1, my level is an advanced B2), so it would be very useful if I don’t have to go through the course.

by skyper_mark