Hello,
The Canon MG5765 is mentioned in About AirPrint - Apple Support as a model supporting the driverless AirPrint technology. This means that it can be used without additional drivers from the printer manufacturer (if the printer and the computer are connected to the same network). Have you been using the MG5765 as an AirPrint printer?
When there is a problem, a first step can be to reset the printing system and re-add the printer:
Reset the Mac printing system to solve a problem - Apple Support
Add a printer on Mac - Apple Support
In case of AirPrint, you may also want to try the following power-cycling sequence:
Power off the router, the printer, the computer, and all other devices (iPhones, et cetera). Wait two to three minutes. Power on the router. Wait two to three minutes. Power on the printer. Wait a minute or two. Power on the computer. Finally, power on all other devices.
Software from the printer manufacturer may or may not add functionality. Drivers will be needed for a USB connection.
https://www.canon.com.au/printers/pixma-mg5765/support
If there is a scanning problem:
'You do not have permission to open the application' when using a scanner on Mac - Apple Support .
Canon has some details in https://support.usa.canon.com/kb/index?page=content&id=ART180175 .