If there are no obstructions or paper jams evident, turn off the machine, and unplug the power cord of the machine from the power supply.
Plug the machine back in and turn the machine back on.
If the problem is not resolved, service is required.
For support and service options, sign into (or create) your Canon Account from the link below. My Canon Account
Important
If you disconnect the power plug, all the faxes stored in the machine's memory are deleted.