On the Mac, use the Command + . keys to pop up a menu of Quick Fix suggestions.

On Windows, use the Ctrl + . keys.

Then just select the Quick Fix suggestion that you want to apply to your code.

Example on the Mac:

Press on the gear > Keyboard Shortcuts > search for "quick fix"

It's Ctrl+. on my Linux system.

In vscode v1.71 there are three new commands you can use for navigating in the QuickFix menu to go to previous or next source code actions.

selectNextCodeAction  // to focus the nextcode action
selectPrevCodeAction  // to focus the previous code action
acceptSelectedCodeAction  // to run the focused/selected code action

You can see the default keybindings below that have been removed. Note the - before the command name in two of the keybindings, that removes those keybindings.

You can make these keybindings (in your keybindings.json):

  {
    "key": "alt+u",              // whatever you want here
    "command": "selectPrevCodeAction",  // for v1.71
    "when": "codeActionMenuVisible"
  },
  {
    "key": "up",                 // default removed
    "command": "-selectPrevCodeAction",  // for v1.71
    "when": "codeActionMenuVisible"
  },
  {
    "key": "alt+d",          // whatever you want here
    "command": "selectNextCodeAction",   // for v1.71
    "when": "codeActionMenuVisible"
  },
  {
    "key": "down",             // default removed
    "command": "-selectNextCodeAction",   // for v1.71
    "when": "codeActionMenuVisible"
  }

The recent response by loann reminded me of Visual Studio Code Keybinding for navigation in Quick Fix contextual menu in which I mentioned the curious history of this context key, which went from CodeActionMenuVisible to actionWidgetVisible to codeActionMenuVisible.

There is also an extension presented as a fix: Keyboard QuickFix, but it shouldn't be necessary anymore.

To enable the light bulb, from vscode go to Settings > Search "Quick Fix"

From the option, check to enable the nearby quick fix option.