How to print sprite's position on console of vscode?

Hi! I'm learning how to construct game on playdate and code in lua. I want to know the position of playerSprite while the code is running. The file is based on the sample given by Inside Playdate.

I used print() in playdate.update(). But no matter what I put a string (string or variables) in print(), nothing shows up in vscode.
BTW how to add codes into my post.

I solved it myself. A playdate debug extension is needed! Tutorials haven't mention it.