No matter where you installed your VST plug-ins, you need to define the correct VST folder in FL Studio to make sure that this location is scanned by FL Studio at startup. Read this article to learn how to define the plug-in install locations for your product in Native Access. On a Windows computer, the VST versions of the software can be installed to any location on your hard drive. Note: Watch this video for more information about managing VST plug-ins on Windows computers. You will then be able to use your NI plug-ins within FL Studio.
In FL Studio, Native Instruments software can be inserted via the VST plug-in interface. This article explains how to let FL Studio scan the folder where your NI VST plug-ins are installed.