all train use electric motors at the end point
the hydrogen would be used to power the generator that produce electric to power the motors
same like current train diesel engines, all that fuel is to power the electric motors that really drives the train

hydrogen production comes from fossil fuel lah
deswai i laugh at pipul thinks hydrogen is "super clean fuel" haha

As of 2020, the majority of hydrogen (∼95%) is produced from fossil fuels by steam reforming or partial oxidation of methane and coal gasification with only a small quantity by other routes such as biomass gasification or electrolysis of water.
https://en.wikipedia.org/wiki/Hydrogen_fuel