Can't use platformIO built-in core

Hi everyone,
I’m really new of PIO. I installed PIO in VSC someday ago.
but I cannot use platformio or PIO in the termininal of VSC like this.

if anyone knows what I should do?..

I reinstall platformIO IDE and VSC again and again but it doesn’t help…

This sounds kind of rudimentary, but have you tried to use the buttons at the bottom left of the page? The check mark is used for building/compiling, and the arrow is used to upload your code.