Hi,
The latest printer driver (https://www.canon-europe.com/support/consumer_products/products/fax__multifunctionals/inkjet/pixma_mp_series/pixma_mp620.html?type=drivers&language=en&os=os%20x%2010.9%20(mavericks)) from the Canon support site appears to be for OS X 10.9 Mavericks. This does not necessarily mean that it cannot be used with some later system versions (but 64-bit software is needed for Big Sur).
To begin with, try resetting the printing system and re-adding the printer. Check whether the operating system offers a suitable driver.
Reset the Mac printing system to solve a problem - Apple Support
Add a printer on Mac - Apple Support
If this does not work. you could possibly test drivers for similar models. I noticed that there is an experimental Gutenprint driver for the MP620 as well.
As with any experiment, software conflicts cannot be ruled out, so make sure that you have multiple backup copies of important files (documents, photos, et cetera). Also, be careul when downloading files from the Internet. Download from the printer manufacturer or from other trustworthy sites only. There are several third-party web sites, often with parts of a printer manufacturer's name in their URLs, where you do not know what you get.