Canon MX720 Series Online Manual page 59

Note
Loading paper larger than A4 size
To load paper larger than A4 size in the cassette (lower), press down the lock (F) on the
cassette (lower), then extend the cassette (lower).
The cassette (lower) sticks out of the machine when correctly set. Do not force the cassette
(lower) into the machine any further.
This can damage the machine or cassette (lower).
(6) Insert the cassette (lower) into the machine.
Push the cassette (lower) into the machine until it stops.