Hello Aline,

At the moment, there's no way to upgrade the license from our store, but instead, we'd manually upgrade your license, and our reseller would pro-rate the charge between Basic and Pro annual. 

The upgrade is automatically calculated as a pro-rated charge, meaning the time you spent using the Pro license cannot be deducted, but the remaining time will be deducted from the lifetime license. 

Here's an example: If you bought a Basic Yearly license, that costs $59 (approx. $0.16 per day). After 100 days, you want to upgrade to Pro, which costs $109 (approx. $0.3 per day). Time spent on Basic: $16 Time remaining on Pro: $79.5 So, the price is not Pro - Basic (109-59=50), but instead a pro-rated charge, and you are going to be charged $79.5 - the time that's remaining until the subscription expires.I

If you're alright with that, please let us know and we'll upgrade your license and send you the installation files for the Pro version.