Laravel 6 Paypal Subscription srmklive/paypal issue - php

Question

I added srmklive/paypal package, I want to make paypal subscription. but it gives me this error message:
ErrorException
Undefined index: paypal_link
I am using laravel 6, and srmklive/paypal
Anyone can help me please to solve this issue ?
.env file
PAYPAL_MODE=sandbox
PAYPAL_SANDBOX_API_USERNAME=sb-ig0ex880582_api1.business.example.com
PAYPAL_SANDBOX_API_PASSWORD=3PZ2E986EZWQN2PN
PAYPAL_SANDBOX_API_SECRET=AZ2CBQPbtotiGlFrm1tAtmH-bBO3AfpRNGWDT6e68-yh69V.BeCgl7W6
PAYPAL_CURRENCY=USD
PAYPAL_SANDBOX_API_CERTIFICATE=
PaypalController.php file
public function payment(Request $request)
{
$data = [];
$data['items'] = [['name' => "Monthly Subscription", 'price' => 10, 'qty' => 1,],];
$data['subscription_desc'] = "Monthly Subscription #1";
$data['invoice_id'] = 1;
$data['invoice_description'] = "Monthly Subscription #1";
$data['return_url'] = url('/paypal/ec-checkout-success?mode=recurring');
$data['cancel_url'] = url('/');
$total = 0;
foreach ($data['items'] as $item) {
$total += $item['price'] * $item['qty'];
}
$data['total'] = $total;
//give a discount of 10% of the order amount
$data['shipping_discount'] = round((10 / 100) * $total, 2);
$provider = new ExpressCheckout;
// Use the following line when creating recurring payment profiles (subscriptions)
$response = $provider->setExpressCheckout($data);
$response = $provider->setExpressCheckout($data, true);
// The $token is the value returned from SetExpressCheckout API call
$startdate = Carbon::now()->toAtomString();
$profile_desc = !empty($data['subscription_desc']) ? $data['subscription_desc'] :
$data['invoice_description'];
$data = [
'PROFILESTARTDATE' => $startdate,
'DESC' => $profile_desc,
'BILLINGPERIOD' => 'Month', // Can be 'Day', 'Week', 'SemiMonth', 'Month', 'Year'
'BILLINGFREQUENCY' => 1, //
'AMT' => 10, // Billing amount for each billing cycle
'CURRENCYCODE' => 'USD', // Currency code
'TRIALBILLINGPERIOD' => 'Day',
'TRIALBILLINGFREQUENCY' => 10, // (Optional) set 12 for monthly, 52 for yearly
'TRIALTOTALBILLINGCYCLES' => 1, // (Optional) Change it accordingly
'TRIALAMT' => 0, // (Optional) Change it accordingly
];
$response = $provider->createRecurringPaymentsProfile($data, $response['TOKEN']);
// This will redirect user to PayPal
return redirect($response['paypal_link']);
}