Failed to install board Firebeetle ESP8266

Hello,

I'm trying to install on the boards manager of Arduino IDE the board FireBeetle-ESP8266 using the link :

http://download.dfrobot.top/FireBeetle/package_firebeetle8266_index.json

or

https://raw.githubusercontent.com/DFRobot/FireBeetle-ESP8266/master/package_firebeetle8266_index.json

But none of them are working, it failed with the following error :

Failed to install platform: firebeetle8266:firebeetle8266.
Error: 9 FAILED_PRECONDITION: Platform 'firebeetle8266:[email protected]' not found: getting tool dependencies for platform firebeetle8266:[email protected]: tool mkspiffs not found

Do you know how to fix it ?

Thank you