See https://github.com/espressif/vscode-esp ... URATION.md (especially the bottom config which includes the compileCommands field)

Thank you, that fixed my problem!

Does anybody know why my header files have the error line underneath them but I am still able to compile and send my code to the board? I'm assuming it's the same reason that I am not getting intellisense when I highlight the functions in the code.

I attached a picture of what I am referring to ...