RINEX/obs from BIN/log

Greetings… almost first post here…

I have seen several posts that don’t quite answer my question so decided to ask here:
Using ublox NEO-M8N on Pixhawk, I need to generate an *.obs file for PPK.

I saw a discussions on several forums, one is below:

Also, ublox forums have some info about using u-center to “turn on” RAWX and SFRBX to be able to generate *.obs and *.nav files.

My question: what is the best way to go from Pixhawk BIN or log file to *.obs file?

Can someone point to a good set of instructions?