Bogdan,

I'm assuming you got Pynmea2 from their github or from Python's pip install.. Whoever maintains pynmea2 hasn't updated that package to include LAU and LAA support yet.

Go here https://github.com/DavisChappins/GDL90toNMEA and follow step 3, you need my custom pynmea2 folder. The only change in the pynmea2 folder hosted by me and the default one is that I updated talker.py to include LAU and LAA sentences. I guess if you wanted you can just replace talker.py.

The SkyEcho2 outputs UDP on port 4000? If it uses a different port you can change line 83 in the script to listen to whatever port you need.