VSCode has an built-in function to lowercase, uppercase and titlecase selected text.

1. Select the text to transform. Use Ctrl + L to selected the whole line
2. Open Show all commands. Linux and Windows: Ctrl + Shift + P, Mac: ⇧⌘P
3. Type in the command, e.g. lower, upper, title
4. Wait for auto-complete (like in the animation)
5. Hit Enter