ESP8266-01 with Firebase

During upload the code to ESP8266-01 to communicate with firebase I am facing some problems.
The console showing this error and I actually don't know what is wrong with my code and why this error are coming.

The error is:

Arduino: 1.8.7 (Windows 10), Board: "Generic ESP8266 Module, 80 MHz, ck, 26 MHz, 40MHz, QIO, 512K (no SPIFFS), v2 Prebuilt (MSS=536), Disabled, None, 115200"

In file included from C:\Users\Sunny\Documents\Arduino\libraries\firebase-arduino-master\src/FirebaseArduino.h:22:0,

from C:\Users\Sunny\AppData\Local\Temp\arduino_modified_sketch_291453\sketch_nov23a.ino:1:

C:\Users\Sunny\Documents\Arduino\libraries\firebase-arduino-master\src/Firebase.h:26:25: fatal error: ArduinoJson.h: No such file or directory

#include <ArduinoJson.h>

^

compilation terminated.

exit status 1
Error compiling for board Generic ESP8266 Module.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

Can anyone tell me the solution of this error?
I work with this same code before and it's worked correctly but from few days this error are showing.