Hi,
Go in the menu My account>My subscriptions on our website while logged in with your account.
If you purchased one of our products in the past, you should see a subscription for it.
If the subscription is still active, you'll be able to download the latest version for free and installing it on your website will update your extension.
If the subscription is expired, you'll be able to renew it instead of paying again for the full price.
And regardless of that, you'll also find at the bottom a link to download the latest version of HikaShop Starter, which is free to use/install/update.