idea java newVirtualThreadPerTaskExecutor is a preview API and is disabled by default use --enable-preview to enable preview APIs

This message indicates that the method newVirtualThreadPerTaskExecutor() is a new feature in Java that is still in the preview stage and is not yet fully supported. In order to use this feature, you need to enable preview APIs by adding the command line argument --enable-preview when running your Java application. This will allow you to use the newVirtualThreadPerTaskExecutor() method and other preview APIs, but keep in mind that they may be subject to change or removal in future versions of Java