Login to your ThemeForest account and go to the Downloads tab.
Locate your Spa Lab purchase. On there, you’ll see how many months of support you have remaining, and beside it there’s an ‘Extend Now’ link.
Click the ‘Extend Now’ link, and it will redirect you to the Theme’s item page.
On the right hand side, click the ‘Extend Now and Save’ button.
Once you click the ‘Extend Now and Save’ button, you’ll be redirected to the checkout page. Confirm your payment details and follow the on screen prompts to finish purchasing the extension.