Canon EOS REBEL T7I Basic Instruction Manual page 99

Selecting the AF Area Selection Mode
S Selecting the AF Area and AF Point
Press the <S> or <B> button
1
.
( )
9
Look through the viewfinder and

press the <S> or <B> button.
Press the <B> button.
2
Each time you press the <B>

button, the AF area selection mode
changes.
97