canon mg5520 can't connect to my MacBook pro no scan ability
Canon doesn’t have drivers for that past 10.14 and full functionality is only specified for 10.4 through 10.6. 


https://www.usa.canon.com/internet/portal/us/home/support/details/printers/support-inkjet-printer/mg-series/pixma-mg5220?tab=technicalspecifications


Unless someone with more experience has an answer, donating that to someone running a compatible OS would be my best use of that gear for scanning. Many canon scanners work with macOS Catalina due to updated drivers, so you could also wait for the vendor to work on your scanner or request support from them. I wouldn’t rule out a community driver if someone decides to take that task on and then releases a third party driver.