The solution is straightforward.
Scan both sides separately, then correct each scan as necessary in a Photo Editing App, then using a Publishing App create a two page document of the two scans and export as a PDF.
Way, way cheaper than an expensive scanner or contracting it out to a specialist.
A reasonable scanner like a Canon is c£80, or c£150 for an All in One Printer with scanning features, or you can use Zaphods’ camera or mobile phone technique which is similar to what I do for taking images for my Wife to use in her educational presentations except I mount my camera on a Tripod.
Taking images using “The Zaphod Technique” and a mobile phone will allow editing of the image and correcting its orientation by using the Photo Apps on the device.  BTW there are mobile phone tripod or steady cam brackets available for not a lot of cash.
What operating system are you using?
Some manufacturers specifically Epson only offer limited support and I had to scrap my old scanner as it would not work on Windows 11 and our old iMac could not be forced into seeing the scanner.  Third party work around apps also would not work.