To upgrade from trial version, there are two possible solutions.
License registration is not required if you reference Syncfusion assemblies from Licensed installer. These licensing changes applicable to all evaluators who refers the Syncfusion assemblies from evaluation installer and those who use Syncfusion NuGet packages form nuget.org
Syncfusion license keys are version and platform specific, refer to the KB to generate the license key for the required version and platform. Also, refer this KB to know about which version of the Syncfusion license key should be used in the application.
If you have directly obtained Syncfusion assemblies from NuGet.org and do not have a Syncfusion account, follow the steps to obtain a free 30-day trial license key: