Of course it's voluntary.
It felt so good to stop reporting. First the secretary sent me several reminders by email. I didn't react to those.
After the 3rd month I thanked him for the reminders but answered him, that I didn't "forget" it, so I didn't really need his reminders.
From then on I wasn't reminded anymore.
I felt free and each time they reminded the brothers from the platform to hand in the report I was laughing inside.
So it is voluntary, but they use a lot of psychological pressure to enforce the reporting. I can only recommend to ignore this psychological pressure. Then they are helpless. When you take elders their power over you away, they are helpless like a bug that is on his back.