// Code that reproduces problem here
const json = {
    "firstName": "John",
    "'lastName'": "doe",
    "address": {
        "streetAddress": "naist street",
        "city": "Nara",
        "postalCode": "630-0192"
    },
    "phoneNumbers": [
        {
            "type": "iPhone",
            "number": "0123-4567-8888"
        },
        {
            "type": "home",
            "number": "0123-4567-8910"
        }
    ]
}

const normalizedPaths = JSONPath({ path: `$["'lastName'"]`, json, resultType: 'path', wrap: false })