Debugger doesn't work on VSC ("The preLaunchTask ... terminated with exit code 127")

Question

I'm creating an app with ionic 4 and SQLite on VSC. I can't access to my db.

When I use the debugger, I have the following errors :

• I have a first "alert window" (I don't know what's the real name) with "The preLaunchTask 'tsc:build -tsconfig.json' terminated with exit code 127." (I didn't find the meaning of the error on google)

-> When I click on "show errors" it opens the tab "problems" on the terminal, but it's written "no problems detected..."

-> When I click on "debug anyway", then I have a new "alert window" with "cannot launch program "C:\Users....src\app\categories\categories.page.ts because corresponding JavaScript cannot be found".

-> I've just tried to click on "debug anyway" again, and now I have the message "attribute 'program' does not exist (C:...app\serve)".

Then it proposes me to open "launch.json" but I don't know what to do with this.

Can anyone help me ?

Thanks :)