Manim output shows "X is not in the script"

[Heavenchaos]

I am just getting started with Manim, just installed all Manim requirements. I started with PyCharm, and copied the tutorial codes from the docs, run commands in the terminal and it worked well, the output is an image containing 1 circle and 1 square. well done me!
For some reason, I wanted to switch to VSCode. I opened VSCode and wrote some other codes, intending to create something else. But as I run commands in the terminal, Manim tells me "ERROR: X is not in the script". And more surprisingly, Manim rendered an image showing not the scene I made this time, but the previous scene I wrote back in PyCharm! Still 1 circle and 1 square! OMG ! Im shocked! why would this happen? Would someone plz help...

[Heavenchaos]

OMG I am a fool. I copied code from docs and didnt realize that I forget to change the filename in commands... guys dont laugh at me plz....