Option-G to Option-Command-G MacOS

option_remappers.json

{
  "title": "Remap Useless Option Symbol Keys",
  "rules": [
    {
      "description": "Remap Option-G to Option-Command-G",
      "manipulators": [
        {
          "type": "basic",
          "from": {
            "key_code": "g",
            "modifiers": {
              "mandatory": [
                "option"
              ]
            }
          },
          "to": [
            {
              "key_code": "g",
              "modifiers": [
                "left_option",
                "left_command"
              ]
            }
          ]
        }
      ]
    }
  ]
}

Hello. Can you guild me how to use it in Karabiner? I want to disable special character when type option + letter.