If you find the Canon printer offline, switch off the printer via the Power button. After that, disconnect its power cord from the back. Wait for 30 seconds before reconnecting. After it reconnects, use the printer's power button to switch it again. Give a test print command. 
https://www.printerfixingerror.....com/blog/canon-prin

How to fix canon printer offline on Mac and Windows?
Favicon 
www.printerfixingerror.com

How to fix canon printer offline on Mac and Windows?

Is your Canon Printer offline? Try these troubleshooting steps - remove the faulty driver, check default settings, Turn on the spooler service