I'm trying to extract value on PHP from this response

{
    "id": "pi_1FxfIlJtivvUT2vVGgfaIWIZ",
    "object": "payment_intent",
    "last_payment_error": "",
    "livemode": "",
    "next_action": "",
    "status": "succeeded",
    "amount": 538,
    "charges": {
        "object": "list",
        "data": [{
            "id": "ch_1FxfImJtivvUT2vVs7YQPJUb",
            "object": "charge",
            "amount": 538
        }]
    }
}

When I try:

$payment_intentID = $payment_intent->id;

It works, but when I try:

$payment_intentID = $payment_intent->charges->data->id;

I get null.

What's the problem?