Arduino for STM32

Hi, I am looking for the definition of the serial channels for the maple-style boards.
I use Arduino IDE 1.8.12 and the latest core from githup.
Apparently, the identifier
Serial represents the USB serial port.
What is then the name of the physical ports? I tried Serial2, but this produces an "undefined reference" error on compilation.
Is there an official document?

If you enable the USB then Serial is mapped on SerialUSB else it is mapped on the default Serialx
For the BP an maple, you can use Serial1 (PA10/PA9).

For other you can refers to https://github.com/stm32duino/wiki/wiki ... wareserial