The first step is to ensure you have the required effects plugins in your system. Some may be there by default, but you should still download the ones you need from the web. Fortunately, many are available for free, while others more developped or specific are sold commercially. You can google "free audio effects", or for a specific one, something like "best reverb plugin" and carry on from there.
Now an important thing to understand is that these plugins come in various standard formats, these are usually:
Usually when you download a plugin, the different formats are installed all together. But if you are on Windows, you would need the VST (VST3 ideally) format, while if you are on MacOS you should go for the Audio Units one.
Once you have installed the plugins you want to use in your computer, you need to make them available to SwarShala. For that, all you need to do is to run a scan, and the valid plugins will be automatically recognized by the software.
Just proceed as follows:
This will launch the scan and add valid plugins to the list. You may get some warnings or even error messages in case a plugin cannot be validated. You can skip that in case you don't need that plugin. Then close the Scan Plugins window. These effects should now be available to customize the sound of your Practice pane or of your tracks in the Compose pane (Tracks view).