Once you’ve created the folder to hold downloaded third-party plugins, the next step is to make sure that Paint Shop Pro knows where to look for them. To do this, open the File menu on Paint Shop Pro’s main toolbar, select Preferences and then click on File Locations. (Click the image below for a larger view.)

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In the File Locations window that appears, select Plug-ins from the list of File types.

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Click on the Add button and locate the folder that you created in the previous section to store your plugins.

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Select that directory and then click OK to continue. The new directory will now be seen in the list in the File Locations window. Click OK again to exit the window.
Now, each time you download a third-party plugin, make sure to either install it in this directory or add the directory that you do use to the list of plugin file locations. This will ensure that Paint Shop Pro recognizes the add-on so you can use it right away.
One extra little thing to note is that you may need to close and restart Paint Shop Pro for the plugin to load in the software.