Get name of newly added interface in udev/rules to pass it as a parameter to a shell script

Hey I'm a bit desperate. I'm trying to get some help writing a 
udev/rule. My problem I also posted on UNIX.stackexchange.com

https://unix.stackexchange.com/questions/743890/get-name-of-newly-added-interface-in-udev-rules-to-pass-it-as-a-parameter-to-a-s

Basically I'm trying to get the name of the interface of a newly added 
usb lte stick which I tried with:

SUBSYSTEM="net" ACTION="add" ATTRS{idVendor}="12d1" 
RUN+="/home/some/interface_test/dosomething.sh '$attr{bInterfaceClass}'"

But there is nothing being passed over. I also tried it with the %m %b 
listed in the man pages but not the right information is being passed.


Cheers

Dorian