What is shortcut for expand-collapse sections of code in VS Code?

Fold or Collapse All:

• Windows, Mac and Linux: Ctrl + K, Ctrl + 0

Unfold or Expand All:

• Windows, Mac and Linux: Ctrl + K, Ctrl + J

Note: In Mac 'Ctrl' buttons looks different, text of which, I am not able to add due to editor limitations.

Please take a look at the below GIF, I am using VS Code in Windows and using Ctrl + K, Ctrl + 0 to collapse all regions of code

More VS Code Shortcuts in Windows related to code collapse

Ctrl + K, Ctrl + 0: fold all levels (namespace, class, method, and block)
Ctrl + K + 1: namspace
Ctrl + K + 2: class
Ctrl + K + 3: methods
Ctrl + K + 4: blocks
Ctrl + K + [ or Ctrl + k + ]: current cursor block
Ctrl + K + j: UnFold

You should also have VS Code user settings, Fold enabled, which you can check using JSON settings

{
    "editor.showFoldingControls": "always",
    "editor.folding": true,
    "editor.foldingStrategy": "indentation", 
}

That's it.