Here are some instructions to explain how this can be done.
License Upgrade Path
Let’s say you’ve purchased a Single Site license, then after a while of using our plugin you needed to upgrade to a higher license package so you can activate the plugin on more sites.
Login to your account dashboard, and go to the Purchase History > View Licenses > Upgrades.
If the license you have purchased has an upgrade path, you will see a link to check out and purchase a higher license by paying only the difference.
If there is no upgrade path in your purchased license, you will see “No upgrades available” message.
So, if you are upgrading to a higher license package, you will only pay the difference.
We’ve made it this way to save you money on your upgrades.