I get to the room with the 2 urns and i went through one of the gate but in a room with fire in it i cant get through the gate i ve tried running and putting a crate on it and it doesnt work...

I suppose you are in the room with several fires and a gate at the end?

Just go back a bit. There is a lever at the wall, which opened the gate into that area. Then run (all your party should be maximum health) and the other gate will be open for a while or open when you step towards it. It is just a matter of timing.

Use two crates. I got through with two crates. Push them right up to the gate, step in the healing fire to open the gate. When the gate opens hold down shift (run mode), and go! But don't go too far!!! You can jam the two crates under the gate. It will keep going up and down as it tries to smash the crates (luckily the crates can't be destroyed, which is damn good craftsmanship). Now walk up to the crates and push them. You should also push past the gate, but be in full health, you will take some crushing damage (you are not as indestructible as the crates, y'know).