It will depend upon state laws and insurance guidelines normally if an insurance company will pay for repairs if you are going to fix your car on your own instead of use a repair shop for damages to your vehicle.
Many insurance companies will want to pay a repair shop directly for fixing the vehicle. If you want to fix your own car, discuss this with the insurance adjuster assigned to your claim and see if this is an option. If the check for the repair amount is made out to you personally then typically you can decide on where you want your vehicle repaired, including buying the parts and repairing the vehicle yourself.
Now if your vehicle has been declared a total loss but you want to keep it and repair the vehicle yourself then you may have this choice, depending again on state laws and the insurance company's guidelines, but you would have to pay salvage value to the insurance company or deduct that amount from your settlement. You will not get the option to keep the car to fix it without paying the insurance company salvage value for it.