Canon WFT-R10A Wireless File Transmitter for EOS R5 C & R5 Mirrorless Camera - Manual (Page 16)

3.
Remove the battery compartment cover from the camera.
4.
Attach the battery compartment cover to the holder.
Insert the hinge ends of the battery compartment cover in the holder.
Press the battery compartment cover to secure it.
To remove the battery compartment cover, slide the lever of the battery
compartment cover to release it, and then follow the attachment
procedure in reverse.
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