Steps to run it

https://arduino-esp8266.readthedocs.io/en/latest/ota_updates/readme.html

create "include/wifi_credentials.h"

#ifndef __WIFI_CREDENTIALS_H
#define __WIFI_CREDENTIALS_H

#ifndef STASSID
#define STASSID "ssid"
#define STAPSK  "key"
#endif

#endif // __WIFI_CREDENTIALS_H

platformio.ini

change IP of esp8266 accordingly IP gets printed on Serial Monitor after first Upload