Stripe payment integration in laravel for buying subscription

I have a requirement to buy subscription that is present.

I do no know how to implement this.

I am implementing in the following way, although this code I have got from a website :

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use Stripe;
use Exception;
use Illuminate\Support\Facades\Validator;
use Stripe\Exception\CardException;
use Stripe\StripeClient;

class StripePaymentController extends Controller
{
    const COMPONENT_CODE = 'RS_PAYMENT';

    private $stripe;

    public function __construct()
    {
        Stripe\Stripe::setApiKey(env('STRIPE_SECRET'));
        $this->stripe = new \Stripe\StripeClient(env('STRIPE_SECRET'));
    }

    public function payment(Request $request)
    {
        $validator = Validator::make($request->all(), [
            'fullName' => 'required',
            'cardNumber' => 'required',
            'month' => 'required',
            'year' => 'required',
            'cvv' => 'required'
        ]);

        if ($validator->fails()) {
            return $this->returnErrorResponse(self::COMPONENT_CODE, 101, array_column( $validator->errors()->messages() , 0), 422);
        }

        $token = $this->createToken($request);
      
        if (!empty($token['error'])) {
            return $this->returnErrorResponse(self::COMPONENT_CODE, 102, 'Invalid token', 422);
        }
        if (empty($token['id'])) {
            return $this->returnErrorResponse(self::COMPONENT_CODE, 102, 'ID does not exist', 422);
        }

        $charge = $this->createCharge($token['id'], 2000);
        if (!empty($charge) && $charge['status'] == 'succeeded') {
            $returnArray['status'] = 'Success';
            $returnArray['message'] = 'Payment Successful';
            return response()->json($returnArray, 200);
        } else {
            return $this->returnErrorResponse(self::COMPONENT_CODE, 102, 'Payment failed', 422);
        }
    }

    private function createToken($cardData)
    {
        $token = null;
        try {
            $token = $this->stripe->tokens->create([
                'card' => [
                    'number' => $cardData['cardNumber'],
                    'exp_month' => $cardData['month'],
                    'exp_year' => $cardData['year'],
                    'cvc' => $cardData['cvv']
                ]
            ]);
        } catch (CardException $e) {
            $token['error'] = $e->getError()->message;
        } catch (Exception $e) {
            $token['error'] = $e->getMessage();
        }
        return $token;
    }

    private function createCharge($tokenId, $amount)
    {
        $charge = null;
        try {
            $charge = $this->stripe->charges->create([
                'amount' => $amount,
                'currency' => 'usd',
                'source' => $tokenId,
                'description' => 'My first payment'
            ]);
        } catch (Exception $e) {
            $charge['error'] = $e->getMessage();
        }
        return $charge;
    }
}

Now I am testing with the following request:

{
    "fullName":"TestName",
    "cardNumber":"4242424242424242",
    "month":12,
    "year":2030,
    "cvv":123
}

It shows the error: Invalid token as no token is being created.

Kindly help, where am I going completely wrong, or is there any other way that I can try.