Bluetooth PAN on the Pi Zero W

Question

I have the following problem: I want to host a webserver on my Pi Zero W and access it over Bluetooth. To achieve this i tried to use PAN as underlying layer. The first time i followed this post. Most of all worked fine, I could connect to my pi via PAN using my Android phone. But still some Problems occured:

1. No ip address was set for the pan0 interface on the pi
2. No ip address was set for the bt-pan interface on Android
3. I didn't want to bridge traffic to an other interface

So I wanted static IPs for the interfaces and no bridging. The rest should stay the same. For this I intended to change several things:

1. I changed the /etc/network/interfaces config to: auto pan0 allow-hotplug pan0 iface pan0 inet static address 192.168.0.2
2. Set an ip to the interface on Android

Then the real problems started: I rebooted my pi did the first steps from the post above until i should activate the interface. But this didn't work because the device 'pan0' couldn't be found.

Do you know what I did wrong or even better, how to fix it?