What does the insurance company mean by fixing the loss price?

This sentence means the result of vehicle damage determination.

Vehicle damage assessment means that the loss assessment personnel of the insurance company come to the scene to take accident photos, find out the damaged parts of the vehicle, determine the parts that need to be replaced or repaired respectively, and finally determine the loss amount.

The fixed loss price given by the insurance company is the total loss of the car, but how much will be paid in the end depends on the driver's responsibility for the accident and what insurance is taken on the car. If you find a loss-fixing company to re-determine the loss, you will have to spend more money.