Honda TALON 2021 Owner's Manual page 198

Brakes
Brake Light Switch Adjustment
Refer to Safety Precautions on page 115.
Periodically check the operation of the brake light switch. It is
located near the brake fluid reservoir.
The brake light should turn on just before the brake works.
Adjustment is done by holding the switch body and turning the
adjusting nut. Turn the nut in direction (A) if the switch operates too
late, and in direction (B) if the switch operates too soon.
UNDER LEFT FRONT FENDER
brake light switch
B
A
Servicing Your Honda 191