Do you have to use an insurance check to repair minor accident damage or can you leave the dent and use the money for something else?
No you do not have to use it for your vehicle damage. You can
use it as you wish. You are required to be compensated for your
damage, It is up to you what you do with that compensation. If you
have a Lien holder on the vehicle then you likely have contractual
obligations with them to fix any damage.