Yeah that firmware is good for ESP8266 modules like the ESP-12 which have a lot of IO pins but not helpful for the ESP-01.
You have to re-flash your ESP-01 with AT firmware. https://www.allaboutcircuits.com/projects/flashing-the-ESP-01-firmware-to-SDK-v2.0.0-is-easier-now/ or buy another one. They're cheap.
Also, here's another library ( GitHub - bportaluri/WiFiEsp: Arduino WiFi library for ESP8266 modules ) after you do that. It is recommended by pert who is very knowledgeable about the Arduino.