ESP is powered by an external supply at 3.1 V capable of 1200 mA. It seems to be working, as the WiFi reports as "AI-THINKER_..." on my phone.
I am trying to connect the board to a Windows PC with the PL2303 module - I have tried both directions, with and without level converter, at 9600, 57600 and 115200 baud. The board does not respond or produces garbage in the terminal.