On the DisplayFusion Settings > Functions tab, click the "Download Scripted" button.
Settings > Functions Tab
Double-click the "Randomly Load a Wallpaper Profile" Function in the list. When the Scripted Function editor window opens, click OK, then click OK again to apply the settings.
Scripted Function Repository
Open the DisplayFusion Desktop Wallpaper window, and configure two or more Wallpaper Profiles.
Open the Windows Task Scheduler, click "Task Scheduler Library" in the left pane, then click "Import Task" in the right pane.
Windows Task Scheduler
Locate the XML file you downloaded in step 4 and double-click it.
When the "Create Task" dialog opens, you can customize the interval on the "Triggers" tab if you like. The default is 30 minutes. Click OK to save the Scheduled Task.
Scheduled Task Triggers Tab
To test the newly created Scheduled Task, right-click it, and choose "Run." You should see a tray balloon from DisplayFusion indicating that the "Randomly Load a Wallpaper Profile" Function is running.
Tray Notification for Running Function
When you're satisfied that everything is working correctly, just close out of the Windows Task Scheduler. The Scheduled Task should then run on the interval that you configured.