how to map :%y+ to yank content of a file

[KevinNitroG]

Hi, currently I'm customing in keybindings.json of vscode to yank content of a file like this

...
  {
    "key": "space y",
    "command": "vim.remap",
    "when": "vim.mode == 'Normal' && vim.mode != 'OperatorPendingMode' && vim.mode != 'SearchInProgressMode' && vim.mode != 'CommandlineInProgress' && (editorTextFocus || !inputFocus)",
    "args": {
      "after": [":%y+"]
    }
  },
...

But it doesn't work. I have tried to config with vscodevim config but it doesn't work either.