If your brake light is on, it could be for a number of reasons. The most common reason is that the parking brake is engaged. If this is the case, simply release the parking brake and the light should go off.
Another common reason for the brake light to be on is a problem with the braking system itself. This could be due to low brake fluid levels, a faulty brake pedal sensor, or an issue with the master cylinder. If you suspect there may be a problem with your brakes, it's best to have them checked by a professional as soon as possible.
In some cases, the brake light may come on due to a problem with one of the taillights. This is usually indicated by a bulb failure warning message on the dash. If this is the case, simply replace the burnt out bulb and the light should go off.
Finally, if none of these other issues are causing your brake light to stay on, there may be a problem with an electrical connection somewhere in the system. This will likely require professional diagnosis and repair.