Static IP for my phone

Hello!

Hope it's ok to post in English!

I searched the forums and I heard something about the possibility of getting a static IP for 4 EUR/month from Drei. I don't see this option in "3 Kundenzone". I have already enabled "Open Internet", which was necessary in order to get a routable IP.

Note that I want a static IP for my phone. Perhaps that matters.

So what do I need to do in order to get a static IP?

Thanks!