It's possible that the headlight bulbs need to be replaced if they're dim, flickering on and off, or won't turn on at all.

On a vehicle that travels by road, headlights are among the most significant lights. They offer the illumination that allows the driver to see as well as be seen while on the road. High-intensity bulbs housed in plastic or glass headlamp housings give the illumination.
Headlight bulbs are available in a broad range of forms, sizes, and styles, and they are designed to be easily replaced when they burn out.
You'll find that a blown headlight bulb is one of the most common reasons for failure when doing an online MOT history checker for your car. If your headlights are dim, flicker on and off, or can't even turn on at all, it's possible that the bulb needs to be replaced.
The lights are particularly crucial to the general safety and drivability of the car, especially for night-time driving, because they offer lighting for low light settings especially on roads with no streetlights or on motorways. When headlight bulbs fail, the vehicle loses critical safety and visibility.
This is not only a dangerous, but it might also cause your car to fail a MOT test. Check MOT status to find out when your car's MOT expires and replace any blown out bulbs before the test.