Karabiner-Elements: Map right_option+equal_sign to numpad plus sign (so I can zoom in on freeciv-gtk4 on Mac without a numpad)

right_option_equal_sign_to_keypad_plus.json

{
    "description": "Map right_option+equal_sign to numpad plus_sign",
    "manipulators": [
        {
            "from": {
                "key_code": "equal_sign",
                "modifiers": {
                    "mandatory": ["right_option"],
                    "optional": ["any"]
                }
            },
            "to": [
                {
                    "key_code": "keypad_plus",
                    "modifiers": []
                }
            ],
            "type": "basic"
        }
    ]
}