Touch Bar does not change to f1-f12 when I press the fn key

It’s an issue of macOS, and unfortunately, Karabiner-Elements cannot avoid this issue.
Instead, please change fn+number keys to function keys in Karabiner-Elements configuration.

  1. Import Map fn + number keys to function keys
  2. Enable Map fn + number keys to their corresponding function keys.
  3. You can use f1-f12 keys by fn+number keys.