You can check your support period expiration date, by logging in to your WeltPixel account, and browsing to "My downloadable products" section. You will see the list of all your purchased WeltPixel products. Make sure you added production(live) URL for each product before going further.
In order to extend support period, click the "Buy Support" link for the specific product.
You will be redirected to the "Purchase support services" page.
You have three options to extend you support period: 1 year and 3 years. Select the desired option, click "Add to cart", and proceed to checkout.
If you want to extend support period for multiple products, repeat the above steps.