These vertical plates at the front and rear wings are called endplate and it redirects the airflow around the tires. They are typically made of carbon fiber and are designed to be as aerodynamically efficient as possible while also being as lightweight as possible.
They are also designed to be adjustable, so the team can make changes to the car’s aerodynamics during practice and during the race. Their main function is to shape and direct the airflow around the front tires, which can help to generate downforce and improve the car’s handling.