At this point, we’ve all seen enough ESP8266 ... to the ESP-7 or 12 module (which plugs in via a header, should you need to swap it out), the board features a CH330N USB to UART chip and ...

I am referring to the ESP8266 ... fed by a battery, USB power, or any other 5V supply. As I mentioned earlier you need to pull a pin low during reset to put the module in programming mode.