Removing the vacuum bell

Just purchased the stealth stretcher and I have used it for a few days. My issue is removing the bell suction.

It sucks up really good, but how the world do i release it besides manually breaking the seal of the rubber? Constantly doing this i feel will eventually rip it. Pushing the button at the top doesnt do anything.

I got a chat reply from support saying to just go here instead of answering 🙄

Thanks