Hi, I'm Ashik. Welcome to JustAnswer. I'm reviewing your question now, and will post back with your reply ASAP
Could you please explain the issue you are having ?
Are you trying to scan to your computer ? If so, please follow the steps below;
First download and install latest drivers for your printer, on your computer from here --> https://www.usa.canon.com/internet/portal/us/home/support/details/printers/support-laser-printers-imageclass/imageclass-mf4350d
Select Windows 10 in left column, download and install the following
[Windows 32bit & 64bit] Tool Box Ver.188.8.131.52.mf18
[Windows 64bit] imageCLASS MF4350d MFDrivers (UFR II / FAX / ScanGear)
After downloading the driver and software, open it and follow the onscreen instructions. This will install latest printer and scanner drivers and software. Now you will see an application named Canon Scan or Scan Gear or MP Navigator on your computer. Open it and that application will allow you to scan.
You can also use Windows' Scan app to scan. Click on Start and select Scan app (you can search Scan on the searchbox at bottom left to find it easily). Open it and it will allow you to scan.
The scanned files will be stored on your Pictures or Documents folder.
If you have any difficulty on following the steps above, please let me know and I will continue to help you