Hyundais do not come with a fuel cut-off switch. That is a Ford only feature.
If fuel pump is not running, you need to check the fuel pump relay located in the passenger compartment fuse/relay box. If relay is good, you need to check for power to the fuel pump. The fuel pump is accessible by removing the rear seat bottom cushion:
Disconnect the harness connector and check for 12v when key is turned on. IF present, then fuel pump needs to be replaced:
Are you getting power out of the relay, going to the fuel pump, but just nothing at the fuel pump?
Unfortunately, all you can do is physically trace the wiring harness for any breaks, chafing, and check for where it loses voltage at. There isnt a shortcut at this point, it is just a matter of physically running down the wiring