That isn’t FUEL. Magnets moving electrons in wire has efficiency losses, it’s called ‘resistance’. A static magnetic field is performing no work. It has to move to do work. To cause a change in state requires energy.
This is snake oil and barely high school physics.
I’m rather sure the YouTube guy is running a scam. It would be easy to rig the tools shown with internal batteries such that they ran by battery power, and not by the device as it appears.
But why bother?
Maybe he’s a prankster.
Maybe he’s looking for YouTube hits.
Maybe he’s setting up a company that will fleece investors.
Take yer pick.
I learned as a Cub Scout that if you coiled wire around a screwdriver and attached the wire to a 6 volt battery, the screw driver or nail would become magnetized.
It would appear that the numerous Indian mechanics who have created various similar constant running generators have learned to reverse that process and to use magnets in a process of generating continuous electricity.