Notice: Undefined index: subscriptionId in /var/www/html/commude/stripe-sample-code/invoice-preview.php on line 8

Notice: Undefined index: newPriceLookupKey in /var/www/html/commude/stripe-sample-code/invoice-preview.php on line 9

Fatal error: Uncaught Stripe\Exception\UnexpectedValueException: Could not determine which URL to request: Stripe\Subscription instance has invalid ID: in /var/www/html/commude/stripe-sample-code/vendor/stripe/stripe-php/lib/ApiResource.php:106 Stack trace: #0 /var/www/html/commude/stripe-sample-code/vendor/stripe/stripe-php/lib/ApiResource.php(120): Stripe\ApiResource::resourceUrl(NULL) #1 /var/www/html/commude/stripe-sample-code/vendor/stripe/stripe-php/lib/ApiResource.php(56): Stripe\ApiResource->instanceUrl() #2 /var/www/html/commude/stripe-sample-code/vendor/stripe/stripe-php/lib/ApiOperations/Retrieve.php(26): Stripe\ApiResource->refresh() #3 /var/www/html/commude/stripe-sample-code/invoice-preview.php(10): Stripe\Subscription::retrieve(NULL) #4 {main} thrown in /var/www/html/commude/stripe-sample-code/vendor/stripe/stripe-php/lib/ApiResource.php on line 106