Its like this anon. Hydrogen isn't a magic bullet to save ICE.
A kilogram of hydrogen stores about the same energy as a gallon of gasoline. 33.4 kWh vs 33.7 kWh.
But hydrogen can't be stored in a gas tank. It has to be stored in pressure vessels.
That's what those big yellow things are in the picture, and there's actually a third obscured behind the electric motor at the back.
Those tanks that take up all the space that in a gas car would be the transmission tunnel or an FR car, fuel tank, and rear-transmission or a MR car, all three combined store 5.6kg of hydrogen.
For an internal combustion powered vehicle 5.6 kg of hydrogen is maybe 180 miles of range.
But consider the packaging of an ICE car for a moment. Without seriously sacrificing practicality you're not going to get the 3 big tanks you need for 5.6kg into a car.
Say you come up with a cool design that puts a tiny 3 cylinder engine at the back giving you 2 of those 3 tanks for 3.7kg.
That's even less capacity, and it required serious compromises to the powertrain.
To fit more into a internal combustion car would require even more sacrifices. Its really only ever going to work for dedicated hydrogen ICE track toys or racing series.