Need help about Library #210

Hello Sir, sorry I m new here ,so don't knew about how to send message to you. I want to flash arduino program to my STM32 Bluepill over Serial communication via ESP8266 Wifi ( without webserver uploading and without internet as Soft Access Point Mode). I cant able to understand how to achieve this . Can you please help me in this sirr ? I have also tried your Library "ArduinoOTA" but some points I don't understand .