I looked over Doc Scan by IFUNPLAY's description in the App Store. If this is the app you are using it looks like the only export options are cloud based (DropBox, Google Drive, Box, etc) and WebDAV (a local network file sharing protocol). If you know how (or are willing to research) setting up WebDAV on your PC, then you could use that.
If you use DropBox or Box, you can set up their app on your computer. Storing the PDF's in the cloud from your iPad will automaticallys sync them to the DropBox/Box folder on your computer. You can leave them there, or move/copy to another folder on the computer.
If you use iCloud Drive with DocScan, then your files should be accessible on the icloud.com site in your computer's browser.
You could also, probably, use iTunes on the computer to copy files to/from Doc Scan using your Lightning/USB cable. I don't really recommend this method. iTunes is overly complicated and doesn't always behave itself in Windows.
I use Scanner Pro by Readdle. It is similar to your app, but includes a Wi-Fi network option that lets you copy files to/from your computer over the local network. When you turn it on, the app give you an IP address that you enter into the URL/Search field of your computer browser. You'll get an file UI in the browser. This is what I was hoping for when I looked at the description of Doc Scan, but if they have the feature it's not mentioned.