Add a new board

I apologize for the bad English. I didn’t find my own in the list of boards. Therefore, the question is, can I add a new board to the PX4 autopilot myself, or can only developers do this?

What board is that?

Docs are here: Flight Controller Porting Guide | PX4 User Guide
My suggestion there would be to pick a board that is similar and then start copying and then adapting it to your board.

This is a board from Artery, AT32F407