Canon EOS R5 C VR Creator Kit with RF 5.2mm f/2.8 Dual Fisheye Lens - Manual (Page 63)

Attaching/Detaching EF/EF-S Lenses
Attaching a Lens
Detaching a Lens
All EF and EF-S lenses can be used by attaching an optional Mount Adapter EF-EOS R.
The camera cannot be used with EF-M lenses.
Attaching a Lens
1.
Remove the caps.
Remove the rear lens cap and the body cap by turning them as shown
by the arrows.
63