getting unauthenticated error in phonepe refund api

i am getting problem of getting unauthenticated in the phonepe refund api. also i am using that token in the payment time it's working fine.

$data = $this->getAuthKey();

    $payment = Payment::where('id', $paymentId)->first();
    $token = $data['access_token'];
    // $token = $payment->auth_key;
    $url = 'https://api.phonepe.com/apis/pg/payments/v2/refund';
    $amount = $payment->amount * 100;
    $refund_id = 'REF' . $paymentId . uniqid();
    $order_id = $payment->transaction_id;

    $payload = [
        "merchantRefundId" => $refund_id,
        "originalMerchantOrderId" => $order_id,
        "amount" => $amount, 
    ];

    $response = Http::withHeaders([
        'Content-Type' => 'application/json',
        'Authorization' => 'O-Bearer ' . $token,
    ])->post($url, $payload);

    $response = $response->json();

    return $response;