You can make 2-sided copies by copying single-sided documents onto the front and back sides of the paper.
This function is only available when the original is set in the ADF, not when it is set on the exposure glass.
Change the machine's default setting to apply 2-sided copying.
Preparation for making 2-sided copies
Configure the [Duplex Copy] setting under copy settings.
For details, see Making 2-sided Copies.