Get last record id from subscriptions table in laravel cashier and stripe

I'm having a payment system in laravel cashier and stripe.

In my database I have default stripe's subscriptions table.

public function subscribe(Request $request)
    {

        $user = auth()->user();
        $paymentMethod = $request->payment_method;
        $appId = $request->appId;
        $planId = $request->plan;
        $user->newSubscription('main', $planId)->create($paymentMethod);

       $this->activateApp($appId);

    }

Now I want to know how to retrieve last inserted subscription record id and store it in a variable to access from another function?

via Chebli Mohamed