Canon EOS Rebel T6i W Instruction Manual page 170

D Using the Built-in Flash
If the subject is too far away and beyond the effective range of the flash,

the <D> icon will blink. Move closer to the subject and repeat steps 2 to 4.
FE lock is not possible during Live View shooting.

170
Take the picture.
4
Compose the shot and press the

shutter button completely.

The flash is fired, and the picture is
taken.