How to use built-in target in platformio IDE

I’m a new of platformIO, I used VSC and installed platformIO IDE, and make a ESP8266 project, ESP8266 have a feature of SPIFFS, and it seemed that platformIO include it. I read the docs of here which saied I need run a command to run spiffs.

but I don’t know where I can input the command. if I can config the platformio.ini file to achieve it?

BTW, I installed the platformIO IDE but it seemed that it did install the terminal tool because I cannot run pio or platformio command in VSC.