Press a Key Twice - Rule - Karabiner-Elements.json

{"title": "Rules for Karabiner-Elements | Tested Version: 11.6.0",
"rules": [
     { "description": "Press a Key Twice - Rule - Karabiner-Elements",
       "manipulators": [
              {
    "type": "basic",
    "from": {
        "key_code": "mykey",
        "modifiers": {
            "optional": [
                "any"
            ]
        }
    },
    "to": [
        {
            "shell_command": "osascript -e 'run script \"Replace_Me\"'"
        }
    ],
    "conditions": [
        {
            "type": "variable_if",
            "name": "key pressed",
            "value": 1
        }
    ]
},

{
    "type": "basic",
    "from": {
        "key_code": "mykey",
        "modifiers": {
            "optional": [
                "any"
            ]
        }
    },
    "to": [
        {
            "set_variable": {
                "name": "key pressed",
                "value": 1
            }
        },
        {
            "key_code": "mykey"
        }
    ],
    "to_delayed_action": {
        "to_if_invoked": [
            {
                "set_variable": {
                    "name": "key pressed",
                    "value": 0
                }
            }
        ],
        "to_if_canceled": [
            {
                "set_variable": {
                    "name": "key pressed",
                    "value": 0
                }
            }
        ]
    }
}
            ]
        }
    ]
}