Most probably you only need to replace some capacitors for the voltage regulator.

you have idea of how to do that?

Is the fan controlled by a separate switch or from a cooking hood? Anyhow, you could try to call the manufacturer (Flexit perhaps?) and provide the model number. Or Google make and model number.

thank you.
it is controled by the cooking hood

If it does not rotate when you try by hand, it must be disassembled for repair (not easy), or replaced (not cheap).

The capacitor is Connected to the fan motor and is a cylindrical part With 2 leads coming out from it. Both going to the fan motor that will typically have 3 leads where 2 of these go to the capacitor.
Its relevant information is printed on it as <number>uF and <Number>V, that are the value and voltage rating.

There will typically be two capacitors, either inside the cooking hood, or in a plastic junction box close to the motor unit.

If inside the cooking hood, remove the filter and look for a plastic box with a cover that can be removed.

The manufacturer will provide you parts and may be able to guide you, unless google can...