The Arduino Nano board is also called the "classic" Nano board, that board has nothing to do with your board.
Your Nano Every is not a AVR board and does not have a ATmega328P and not a ATmega168. I did not tell to install the AVR boards.
You have to select your board like this:
The Arduino Team decided to make new boards with the same size and pins like the classic Nano boards and they put the "Nano" in the name of the new boards. That is confusing. Please don't call your board a "Nano" board, because it is not a classic Nano board, it is a newer board called the Arduino "Nano Every".
It is not your fault, others are confused as well with the "Nano" names, and the term "MegaAVR" versus "AVR" is also confusing.