Sometimes when installing a plugin from Plugin Alliance, the factory presets are not properly linked with the VST3 version of the plugin.
No problem, you can easily import them.
Depending on your DAW this process may be a little different, but most DAWs have a button you can click to Import presets, and depending on the DAW, you may also be able to simply drag the preset files in.
For Windows, your Plugin Alliance VST3 presets will be in:
Documents > VST3 Presets > Plugin Alliance
Then just find the proper folder for the plugin you want to import the presets to, grab all of the files, and import.
Check out the video to see how to do it.