You don't need to upgrade your account, it is free to use forever when you register your account.
How will I be charged?
There is no cost to you.
What happens when I delete my account?
You cannot delete your account on your own, you can contact us. We will delete your account within 1 week and once your account is deleted, your subscription will be cancelled and we will wipe all your data from our servers, including but not limited to your links, traffic data, pixels and all other related data.
Why doesn't the Developer API and Import Links work?
In our experience, since we are providing website shortener service for free, turning on Developer API and Import Links can lead to a lot of abuse.