Based on the sample application, its esp_iot_sdk_v1.5.0 firmware that contains: a) bin\at\noboot"eagle.flash.bin" - 0x00000, b) bin\at\noboot"eagle.irontext.bin" - 0x40000, c) bin"blank.bin" - 0xfe000, d) bin"blank.bin" - 0x7e000

The firmwares are required to upload on the esp-07 module to be able use the "WiFiEsp library" in Arduino.

Software and Firmwares: https://www.e-gizmo.net/oc/kits%20documents/ESP8266%20ESP07or12E%20WiFi%20Shield/ESP%20softwares.zip

ESP-12/E Manual: https://www.e-gizmo.net/oc/kits%20documents/ESP8266%20ESP07or12E%20WiFi%20Shield/ESP8266%20ESP07or12E%20WiFi%20Shield.pdf