Hello,
As you may have discovered, the latest supported operating system for a printer driver (Ver. 11.7.1.0) from the Canon web sites appears to be OS X 10.11 El Capitan.
https://www.canon-europe.com/support/consumer_products/products/fax__multifunctionals/inkjet/pixma_mx_series/pixma_mx870.html?type=drivers&language=en&os=os%20x%2010.11%20(el%20capitan)
https://www.usa.canon.com/internet/portal/us/home/support/details/printers/shttps://support.apple.com/kb/DL1928?viewlocale=en_US&locale=en_US
Even though the driver update date is September 9, 2021, Canon apparently has chosen not to support newer operating system versions. This does not automatically rule out any use with a later OS version, but that would be entirely experimental. However, macOS 12 Monterey is special, so do not expect it to work there.
There is a Canon Printer Drivers v3.4 for macOS download at https://support.apple.com/kb/DL1928?viewlocale=en_US&locale=en_US . A Canon MX870 series version 16.10.0.0 driver is mentioned in the referenced article. However, the same here: "Not compatible with macOS v12 and newer" under System Requirements. Anything else would be experimental.
As always, make sure that you have backup copies of all important files (documents, photos, et cetera).
If necessary: Reset the printing system on your Mac to solve a problem – Apple Support (UK)