Hi, if you look at https://fmod.com/resources/documentation-api?version=2.1&page=core-api-system.html#system_createdsp again it has the parameters required for the function.
For the DSP_DESCRIPTION structure start by zeroing it out. Then just set what you need.
This just might be nothing but the ‘read’ callback to get started, and pluginsdkversion is FMOD.PLUGIN_SDK_VERSION
See https://fmod.com/resources/documentation-api?version=2.1&page=white-papers-dsp-plugin-api.html#the-plug-in-descriptor for more on this.